Monday, July 15, 2019

Question Technology

One of the interesting t-shirts I saw at CSTA 2019 last week said “Question Technology.” That might seem to be a strange slogan at a computer science education conference but it really shouldn’t be.

Security of information, privacy, and the ethical use of technology was a constant topic as CSTA. From the Tuesday keynote by Natasha Singer from the New York Times to multiple sessions on cyber security to hallway conversations these were regular issues to discuss and to talk about how to teach. I don’t think there is any disagreement that we need to talk about these issues with our students.

We need a generation that asks “should me as often as can we” do things with technology.

Friday, July 12, 2019

It’s Really About the Teacher

CSTA 2019 gave me a lot to think about. Today I was thinking about what was impressive and I thought about the Tuesday lunch panel. Microsoft brought a panel of high school students to talk about how computer science education was changing their lives.

None of these students talked much about the programming languages they learned or really any of the technology. No talk of robots, or other gimmicks. What they talked most about was their teachers.

They talked about teachers who got to know them as people. Teachers who encouraged them to try new things. Teachers who supported them when they ran into obstacles. Teachers who valued them as people.

New programming languages are cool. Gadgets can help us make things more interesting. When you get right down to it though the key factor is student success is largely dependent in the teacher. I don’t know who said it but it is true – they may not remember what you said but they will remember how you made them feel.

Thursday, July 11, 2019

What do Companies Get Out of Supporting CS Education

After the announcement of a millions dollar grant by Google to CSTA and the new “Code with Google” program I was asked “what does a company get out of this sort of thing?” The answer can be complex.

In many cases, including this one from Google, there is no obvious monetary benefit to the company. In fact the closest thing to a balance sheet benefit is probably goodwill. Now goodwill can be very important to a company. Given the current political scrutiny on companies like Google (and Facebook, Twitter, and Amazon) one would be excused if they saw that as a motivation.
I’m not so naïve as to thing that goodwill doesn’t play into decisions like this one but I doubt it is the whole story.

Companies like Google. Amazon, Microsoft, and others live in an environment that includes many other companies. These huge companies will always attract top technical people but for many companies there is a real shortage of technology people for them to hire. These foundational companies need the companies who build on top of their foundations to also be able to hire technical people. Supporting CS education helps support that environment.

And it is not just tech companies who need these people. All companies need people who at least understand technology. So in many real ways one could call support for CS education enlightened self-interest.

Do companies want students to use their products? Of course and so you will see things like Swift Playgrounds which runs on Apple products and develops apps for Apple products. Or AWS Educate which uses AWS and will probably result in future paying customers for AWS. Again, there is some relationship building that companies hope will lead to future business but the concepts are far from limited to those specific products. There are no guaranties here but they are clearly more about building the company's environment than the specific companies.

Other products though don’t have as clear an path to profit though. Take MakeCode and Makecode arcade developed by Microsoft. These products don’t lead directly into revenue generating hardware or software sales. What they do is develop more people with a knowledge of programming and computer science. That helps the environment.

As I see it, companies are interested in building the CS environment, building goodwill, and possibly getting some business in the future. The degree and priority of those motivations vary by company and even time.

For me as an educator, my concern is about the concepts tools teach, how they motivate or not my students, and generally how they prepare my students for the future. Concerns about privacy and security are of course also concerns. If a company helps me do my job and prepare my students better I see that as a win. If companies get a benefit as well I hope that will encourage them to help more.

Wednesday, July 10, 2019

Random Thoughts on #CSTA2019

I’m pretty sure I have been to every CSTA conference going back to when it was the CS & IT conference and there was no CSTA organization. This year’s was by far the biggest and maybe even the best. But it does feel big. Not ISTE big or even SIGCSE big but big for a conference of CS teachers.

That’s great is many ways. I think there were up to 9 concurrent sessions in each time slot on Tuesday and Wednesday. I remember when there were two. On the plus side you are pretty certain to find a session you are interested in. On the down side you are also likely to find two or three you are interested in at the same time. It’s a fact of life.

It’s not so big that I can’t find most of my friends there but it is something I have to be more deliberate about. And of course on the plus there are many new friends to make. ISTE is too large and there are many people who I know were there but we just didn’t connect. How big does a conference have to be before it loses the closeness that I value so much about CSTA? I don’t know. I do hope the conference committee thinks about that though.

Volunteering was a good thing. I worked the registration desk. It was nice to see and meet people I know and didn’t know. The registration system seemed to work very well. The CSTA staff handled glitches and issues quickly and professionally. That seems to be developing fast enough to handle the size of the conference.

Sessions were all very good. Not everyone was everything I was hoping for but that is to be expected. The quality of the presenters was really high though. I think that the speaker quality is higher at CSTA than ISTE on average.

Comparing ISTE and CSTA is interesting if not exactly fair. CSTA has a specific focus – CS education and CS is one of many topics for ISTE. A number of companies were exhibiting at both and I would love to know how the two conferences compare for them. A couple of companies that were at ISTE were not at CSTA. I was surprised that Unity was at ISTE. I really was. A big booth as well. I suspect they could have reached more CS educators at CSTA for a lot less money. But maybe I don’t understand their goals.

Speaking of the exhibit hall, there was close to 60 exhibits this year. I think we had 6 the first year we had exhibits which wasn’t that long ago. I do feel they add to the value of the conference. Much of the materials being offered were free as well. Obviously not hardware but much of the curriculum and other teaching resources. Lots of it looks like it has been used successfully in a lot of classrooms. By contrast, much of what I saw at ISTE was both more expensive and with less of a track record.

Microsoft and Google both had significant presences at CSTA. They’ve both, though their charitable arms, donated a lot of money to CSTA in the last year plus as well.  Money indicates support but I feel like a physical presence speaks a lot of commitment and seriousness of interest as well. Amazon was there showing a couple of programs including there AWS Educate program and some of their other STEM efforts. Facebook had a small presence as well. It was low key and not at all about selling Facebook to people. The heavy hitters in technology seem to realize the importance of CS education and CS educators. No sign of Apple though. Sigh.

Next year is a day longer than this year. CSTA and CS & IT used to be one day. Then two. Five next year? I have no doubt at all that they can fill it with enough quality content. I do wonder about the expense of attending though. Airfare and conference fees don’t jump that fast for an extra day but hotel rooms can be a big expense.  I’ll wait to see what the schedule looks like and what the hotel costs are before I make my plans for next year. I do plan to go. The question is for how long. I suspect a lot of people will be doing those calculations.

Google and other companies have been helping with scholarships and I hope that continues. It’s especially important for first time attendees. I hope school districts see the value and step up for teachers as well. Arkansas had over 30 people at CSTA and I believe the state kicked in a lot of the money for that. With more and more states mandating more CS education will they also step up with professional development money? I hope so.

My big take away though is that CSTA is the conference K-12 CS teachers should attend if they can only attend one conference. Hope to see many of my readers at CSTA 2020 next July.

CSTA 2019 Day 3

So I missed the opening keynote which I am sure was amazing but I spent the time catching up with a good friend who I see too rarely. Time well spend. Leigh Ann Delyser from CS for All sometimes talks about the CS community as her grown up summer camp friends. I have to agree. The face to face time with friends at a conference makes the communication between in real life meetings much better.

My first session of the day was a panel about advancing equity and diversity. It really focused a lot on curriculum and how to teach to ALL students. Not a limited focus on girls or under represented minorities but a realization that diversity requires welcoming environments for ALL students. There was also some good discussion about creating projects that are open and inclusive for students of different abilities and backgrounds. This is just one time when curriculum in general and finding the right projects for the classroom. I need to think about writing up more on that topic.

My last session before lunch was a series of three mini sessions. The first was on Engage CS Edu. This is a curated site with projects of various types and concepts for CS educators. It is “Foster diversity in your introductory computer science courses with quality content and engaging pedagogy” This looks very helpful as I am always looking for engaging projects that work with diverse students.
The second mini-session was on How to effectively Manage a CS class and was mostly about how CodeHS helps this teacher manage his courses. If I were looking for a new curriculum I would take a serious look at CodeHS. CodeHS has both free and paid levels.

The third mini-session was Building a Cyber Center for Excellence. They seem to have a very impressive cyber security center at Grand Canyon University. I don’t think a lot of it is reproducible in a high school but some of it it. The speaker has a free guide containing High School Cybersecurity Education Websites and Resources which  I did download and a not free ($3.99) ebook called “Beginner’s Guide to Developing a High School Cybersecurity Program” so I can learn more.

Overall, a very good conference for me. I learned a lot and I have ideas for the new school year.

Oh and next year’s CSTA Conference will be July 11-15 in Arlington Virginia.

Tuesday, July 09, 2019

CSTA 2019 Day 2

I’m always skeptical about celebrity keynotes at education conferences so my expectations for Natasha Singer from the New York Times.were not high. I was pleasantly surprised though. She gave me a lot to think about when teaching things like ethics, accountability, and privacy. Things like what the saved wi-fi networks our computers save and share to how companies track individuals and more. A good keynote should give attendees things to think about and things to act on and this one did that for me. So great start to the day.

There were any number of sessions I would have liked to have attended and I think information about them (videos maybe and hopefully others blogging) will show up. For now I am writing something about the sessions I am attending.

My first session of the day was “Soaring through the Cloud” by AWS Educate. If nothing else people are getting a good look at the vocabulary of the cloud. Vocabulary is something I see as key. I was impressed that AWS wants schools they partner with share their curriculum and programs with other schools. Diversity is important to them. The AWS Educate program includes free cloud accounts, online training, and badging for successes. There is a ton of content there. I could see a special course around this.

Also AWS has been very responsive to teacher and school worries about student privacy and security.  Very important!

I didn’t have to move for my second session of the day – Using GitHub as a Content Management System. Another packed house. This was a good walk through of GitHub for me. As a total beginner it was pretty helpful..I still have a lot of playing around to do but it does seem really usable.
Lunch had a set of trivial games that we surprisingly fun followed by a panel run by Microsoft. The panel was of high school students who were talking about the influence of taking computer science courses on their lives. The students were from schools supported by volunteer TEALS instructors.  These students were from schools in low economic areas that would probably not have CS without the work of TEALS volunteers – industry professionals giving their time to teach students. It was an inspiring session. Oh and the food was pretty good too.

Afternoon took me to a session on Machine Learning. Teachers talked about teaching machine learning both as a concept and at a technical level. There are a couple of neural network “playgrounds” including the tensor flow website from Google that I want to use to introduce the ideas to students. There is a link to resources ( ) that I plan to explore.

Last session of the day for me was Nifty Assignments. We could have used a bigger room. This session was worth getting there early for.The new CSTA Nifty Assignments page has all of the references to the sessions. Five interesting projects with something for everyone. from K-5, to 6 – 8 to 9-12. I’m inspired to have my students do more graphics by the digital coloring book projects and have some great ideas about using letter frequency counts. Oh and last year’s nifty assignments (which I missed) are also linked there. This is only going to be a better and better resource as time goes on.

For me the day finished with dinner with David Renton who taught college is Scotland for years and who now teaches high school in the US. Great conversation about teaching and differences and similarities in education in two different countries. You really can meet the best people at CSTA.

Monday, July 08, 2019

CSTA 2019–Day 1

As planned I spent most of the morning helping at registration. And talking to a lot of people as they came in. After lunch the exhibit hall opened and I was in there early. A few highlights:

A virtual reality version of Alice is coming in the fall. I had a demo wearing an Oculus headset riding through an Alice world. Very awesome. Virtual Reality and Alice – Wow!

I signed up for GitHub for educators. GitHub classroom looks like a good way to send starter projects to students. I have a lot of exploring to do but there is online training for teachers so I’ll start there.

I had a demo of CodeSpace from FiriaLabs for teaching Python. They have a robot that looks pretty cool as well. Still not sure robots are my think but their connection to Micro:bit looks pretty nice as well.

Code Jumper is a program developed by Microsoft for blind and visually impaired students. It involves physical devices that are a coding language. Think block languages where the blocks are actual physical blocks The teacher who showed it to me tells me that she has used these devices (not available yet but she is in a pilot) with ADHD students  They get very engaged.  I can really see this useful in a lot of situations. Availability is some time in the fall. I have no idea of pricing.

The welcome reception was top notch.  I ate my fill and have no need to a later dinner. Better still was the opportunity to talk to even more people.

BTW, in my last post I mentioned Google’s new Code With Google program. It’s a good collection of resources for teaching computer science. Check it out at

CSTA 2019 Day 0

Sunday was the start of CSTA 2019 with workshops and the Chapter Leadership Summit. I wasn’t part of the summit and I didn’t get to any workshops but I still had a good day. I did crash the reception Google hosted for the chapter leadership summit though. Jake Baskin announced a million dollar grant to CSTA from Google and Google’s new “Code with Google” program. I expect to learn more about both as the conference goes on.

The highlight of the day was spending time with friends. I’ve been to every previous conference (going back before there was a CSTA) and in the early days it was much smaller so I made a lot of friends back then. I’ve made still more friends by being involved – volunteering in different ways. I had dinner with 10-11 friends almost all of whom had been on the conference committee with me, the CSTA board with me, or both. Besides helping the CS community, volunteering with CSTA is a great way to make friends.

I wonder how it is for people new to CSTA. It’s so much bigger today and while that is wonderful in many ways I can see it being overwhelming for some as well. My hope is that people expand their connections beyond people they may have come with or know from elsewhere.  Diversity is really important. Part of what made last night’s dinner so interesting for me was people from a number of different states and two countries other than the US.

Diversity came up in a number of contexts yesterday both in conversation and in he Google announcements of yesterday.  Companies in the industry are starting to really appreciate the importance of it but I really believe that as educators we have an important role in fostering diversity from the start.

Today, Monday, I will be working the registration desk for a while this morning, visiting the exhibit hall in the afternoon, and trying to connect with as many people as I can. Learn from the best I often say. If you’re around come find me. I am wearing my hat and I have “I Follow @AlfredTwo” ribbons if you’re interested.

Sunday, July 07, 2019

Pre-conference Thoughts–CSTA 2019

I’m on my way to Phoenix AZ for the CSTA conference.  For years I would get there early and leave late. This was especially true when I was on the CSTA Board and there were Board meetings to attend. Traveling on my own dime and my own schedule this trip. This afternoon I will be helping at the registration desk. I’ll also be helping there tomorrow. Volunteering at CSTA is a small thing in some ways but I think it is really important to make some contributions. Plus it means I get a jumpstart on the “Hallway Track” that is part of what makes CSTA so wonderful.

Sunday and Monday are workshops and I didn’t sign up for any. That’s new for me but Monday afternoon the exhibit hall will be open and I really want to get to that. Almost 60 exhibitors this year. I think we had 6 the first year we had exhibitors. This shows how important CSTA is to so many companies, universities, and other groups supporting CS educators. Plus it is a great opportunity for educators to learn and have one on one personal conversations with exhibitors.  I’m a big fan of exhibit halls at conferences though I know not everyone is.

Unlike ISTE, where I was recently, the focus on CSTA is all computer science and the exhibit hall reflects that. One doesn’t have to search for relevant booths and it is still small enough that you are unlikely to miss something.

Tuesday and Wednesday I have lots of sessions in my app. I’m looking forward t o Mike Zamansky’s session on using GitHub as a CMS. There is also a session from Amazon Web Services on introducing the Cloud to students. Another key technology there! And a Nifty Assignments session to cap of  the day.

I’m still deciding on Tuesday. There are several sessions I’m interested in that are at the same time. A common problem, but a good one to have at a conference.

I have no idea what the “hallway track” will bring. I have so many friends at CSTA and they are doing so many interesting things. Learning from other teachers is really awesome. CSTA almost feels like a family reunion sometimes.

Sunday, June 30, 2019

ISTE 2019 Trip Report

There was a time when I would have written a blog post every night of ISTE. Apparently I’m getting older or something and that is not a priority for me any more. Be that as it may I got some good stuff at ISTE this year. ISTE is not all about computer science the way CSTA (next week) or SIGCSE are but there is more CS than their used to be. You have to hunt for it a bit though.

Robots were big again this year. It seems like everyone is pushing robots as the silver bullet for teaching CS. I’m not so convinced and most of the robot stuff was aimed at younger students. K-6 or K-8 were big. Lots of people promoting their drag and drop Blockly-like programming tools. If you push you hear about Python and other text based languages.  I didn’t spend much time with robots. I don’t want to build my course around them. If others do that is fine. It’s just not me.

On the other hand I am interested in internet of things and integrating that into some of my courses. Plezmo has some interesting products in that space. I missed them in my walk through the exhibit hall but Alark Joshi, Associate Professor of Computer Science at the University of San Francisco, sent me an email suggesting I check them out.  I’ve got a core kit ordered. I plan to use it for some experimentation on my own but also as a way to introduce IoT to my students in several courses. Should make for some good demos. Later I may add it to my curriculum. A lot depends on my experimentation.

Doug Bergman gave a presentation on using Artificial Intelligence in projects using some tools from Amazon Web Services (AWS). Doug demonstrated using these services from Thunkable  This may be the piece that really makes my mobile application development course take off. You can learn more about AWS Educate at this link.

Unity also had a surprisingly big booth at ISTE. They have some free online courses which would be usable in the classroom. If I were to have a game development course I would go there first. As it is I plan to take some coursework myself and see how it might fit in to an existing course or perhaps into a new project course I want to propose at my school.

This relates to something else I found interesting at ISTE. Steve Demo presented on Virtual Reality in education. The Oculus Quest (which I got to try out) is pretty awesome and it is programable using Unity and C#. This combination might be awesome in a course after my Programming Honors or our AP CS A course. First I’ll learn some Unity and then I will look at AR/VR/MR devices to see what is practical in the classroom.

I did talk to someone from the Azure (Microsoft’s cloud offering) at the Microsoft booth. I will follow up to learn more about their options as well.  GitHub is something I really want to bring into my Programming Honors course next year and Microsoft owns GitHub now. GitHub for education will be at CSTA and Mike Zamansky is presenting a session on using GitHub so I’ll be in better shape there after CSTA.

So I enjoyed ISTE and I got some good value out of it. But because ISTE is so large a lot of the CS stuff (and people) get lost. CSTA will be a whole other story. Can’t wait to get there.

Sunday, June 16, 2019

In Honor of BASIC

I found an interesting article today New Hampshire installs first historical marker to honor computer programming The BASIC programming language was invented at Dartmouth College in New Hampshire. Today it gets a bad rap and perhaps the original version deserve it compared to modern programming languages. For its time though it was pretty important.

The early personal computers all came with some version of BASIC.There were books one could buy that has listings of BASIC programs that we used to enter and play with. A lot of people got their start in computer science by teaching themselves BASIC.

The first language  I learned was FORTRAN but the next year my university got a Digital Equipment PDP-11 running the RSTS/E operating system. It cam with a great version of BASIC called Basic-Plus. I taught myself that on my spare time. As an interpreted language on a time sharing system, unlike the compiled FORTRAN on a batch system, this allowed a lot more and more frequent experimentation.  That really opened things up for me.

After university, knowing Basic-Plus got me my first professional software development job.

Later I learned Visual Basic and then Visual Basic .Net. Today’s Visual Basic is a far cry from the original BASIC of course but a lot of the basics are the same. There isn’t much you can do in C-family languages that you can’t also do with Visual Basic. And it is still more friendly for beginners than Java or C++ or C#.

It is still looked down upon by many and yet as the same time it still shows up on lists of most used languages (

These days I use C# for a lot of my personal programming but I still like to use Visual Basic (as I did for a quick hack today) Over my career versions of BASIC have been very important to me.

Thursday, June 13, 2019

Teaching Students to Yearn to Learn

Summer time is time for me to do a lot of thinking about my teaching practice. I've been doing a lot of reading and a couple of quotes have helped me in my thinking. Two of them are about leadership and I see them as having applicability in education. A good teacher is a leader - trying to lead students to learn. The first quote is about using coercion.

“You do not lead by hitting people over the head — that’s assault, not leadership.” – Dwight D. Eisenhower

Grades are, or can be, a bludgeon. Sometimes teachers use grades as a way to force students to do work. I hate doing that. It feels like a metaphoric "hitting over the head." It may get students to do some work or at least to hand in something but it seldom really leads to real learning. That leads to the second quote I have been pondering.

“If you want to build a ship, don’t drum up the men to gather wood, divide the work, and give orders. Instead, teach them to yearn for the vast and endless sea.”
― Antoine de Saint-Exupéry

Leadership is largely about teaching students to yearn to learn. A good teacher leader develops internal motivation in their students so that they want to develop the knowledge and tools one is trying to teach.

One of the things I have observed is that students who have a say in the projects they take on are much more motivated to learn the things they need to know to complete them. Getting students to want to learn is much more effective than trying to force them to learn so that they can get good grades.

Wednesday, June 12, 2019

Different Kinds of Professional Development for Computer Science Teachers

What to teach and how t teach are different questions. The first is all about content knowledge and the second is about pedagogy. For the most part it feels like professional development for CS educators is focused almost completely on content knowledge. A great many teachers are coming to computer science from teaching other subjects. There is this idea that a good teacher can teach any subject once they have the content knowledge. I’m skeptical. Computer science is not quite like other subjects. It’s more like teaching vocabulary and novel writing at the same time. We’re teaching how to write a novel to people who not only have never read a novel they don’t even know what the words mean.

Do I exaggerate? perhaps a little but the point is that we probably shouldn’t assume that teaching CS is the same as teaching other subjects. There is not a lot of professional development on how to teach CS.  We sure could use more of that.

Although if I am honest, we could use some deeper content knowledge training as well. It seems like most of what we see is pretty basic and designed for beginning teachers. But we all need more research based knowledge about how to teach what we do know.

BTW, Garth Flint had a nicely related post on his blog

Tuesday, June 11, 2019

Join the Online #CSed Conversations

At it’s best, social computing is a conversation that moves in a positive direction. The more people who participate the better the conversation and the more benefit for everyone involved. For computer science teachers, who are often alone in their school. opening and participating in online conversation can be a real benefit. These conversations can cross boundaries of time, space, and even online environments.

A recent example. Garth Flint wrote an end of year post (Last Day of School And Done with Java) that I lead to a post of my own. (How Well Can You Code the Projects You Assign Students?) Mike Zamansky wrote a follow up post of his own. (Do It First ) All of these posts were also discussed in Facebook and Twitter. And of course there are comments left on the various posts. So there are multiple ways to participate in the conversation.

No one has to participate in all the conversations or all online tools/communities to benefit though. Things, especially good ideas, tend to propagate across paths. That’s how networks work after all. There are enough people who act as transmission nodes that the best knowledge and the best ideas tend to move around pretty widely. Everyone benefits from this. People who lurk (read and don’t respond) learn a lot which is an almost invisible benefit. At least it is usually invisible to the people who are writing but it is probably pretty visible to the students whose teachers take what they learn and use it to better their own practice.

Still I wish more people took an active part in the conversation. Be it a comment on a blog or Facebooks post. A tweet with a link and a comments.Tweets in a Twitter chat.  Or an original blog post of their own. (I REALLY wish more CS teachers blogged about what they are doing.) How ever people participate we all benefit.

Computer science educators tend to be a very supportive community. Jump in with both feet.

Sunday, June 09, 2019

Change the Programming Language, Change the Course

A recent Facebook post suggested changing the language for Advanced Placement Computer Science A (what some of us annoy others by calling AP Java). This comes up regularly with lots of people suggesting their favorite language. Changing the programming languages means changing a lot more than the language though.

Different programming languages have their own idioms. Their own way of doing things. Programming languages and the concepts one can teach with them are closely related.The change to Java (and to some extent C++ before it) was based on a desire to teach more object oriented programming and design. The language was picked after the concepts to teach were chosen.

I wonder how often we (CS teachers) pick a language first though. DO we pick the concepts to teach based on the languages and the programming idiom we are familiar with or do we  think wider?

My honors programming course is largely a warm up for AP CS A and preparing students with the concepts they’ll need is a goal. I use C# rather than Java though because it seems to me (without the sort of research based evidence I should probably look for) that it has a lower cognitive load than Java. It seems to work for us.

My APCS Principles class is using the curriculum and tools developed by It uses their block based App Lab with the option to use/view JavaScript. This language and tool does appear to be based on the concepts rather than fitting the concepts in after the fact. So I’m happy with that.

One thing I will be pondering over the summer is what concepts should I teach. Am I teaching the right concepts or should I change them? What about cognitive load? I was re-reading How to choose programming languages for learners: Reviewing JavaScript and Ready by Mark Guzdial and his points about cognitive load really resonate with me.

Block languages do seem, based on evidence, to have lower cognitive load for beginners. I’m less comfortable with them; probably because I’m so old school. Student attitudes towards them are mixed with some really loving the low cognitive load and some having trouble taking them seriously. I have to keep in mind the concepts I want to teach as well.

No matter how I look at it though it is never as easy as “just teach the same things the same way but with a different programming language.”

Friday, June 07, 2019

How Well Can You Code the Projects You Assign Students?

Garth Flint had another good post today (Last Day of School And Done with Java) He lists some interesting projects he assigned and writes about some lessons learned. Any time a teacher learns from student projects I count that as a double win. But one of his comments really resonated with me. Garth writes “I did only two of the six assignments myself.  With the others I saw the solution so did not code them up.  I should have coded them up just so I could answer questions better for the students. “ Highlight mine.

Some years ago I wrote a couple of editions of project books for both C# and Visual Basic. (I may update them this summer if I have time.) People seemed to like them and I received numerous requests for coded solutions. I had them and usually provided them. I really think that teachers should always write their own solutions though. In fact, the less you know about programming the more you should code up your own solutions. As Garth pointed out in his post, when you code your own solutions you can better help students.

And if a project is a good learning experience for students it will also be a good learning experience for a teacher who is working on their own skill and knowledge base.

I’ve got a ton of programming experience and know a lot of tricks techniques that I would never expect beginners to know. So I try to write solutions using the tools and language constructs my students will have at their disposal. This helps me understand what issues students are likely to come across. It saves me time later.

Of course students are clever and think of ways to do things that an experienced coder would never come up with so I learn some new things from them. And the smart kids look up features we don’t cover in class and build “interesting” solutions. That’s all good. Better than good really. I’ve actually come up with several new to me ideas from students.

To be clear, I don’t want every student to write their solution the same way I write mine. I want to see some creativity and imagination. But I also don’t want to have to admit I have no idea how to implement a solution of my own. Well, not often anyway.

Since I teach several level of CS from our freshmen course which only has a few weeks of programming to our APCP P course with Programming Honors in the middle I sometimes code up several solutions. Some things that are possible with limited tools are much easier with more advanced tools. Arrays for example can be a powerful tool. I wrote about this a couple of years ago at Taking Things To Another Level  where I talked about revisiting a popular freshmen project later in Programming Honors.

It’s summer break and I’ll be doing some coding. Trying new projects to see what students will need to know to code them themselves. I’ve been looking forward to having the time to do this for moneys.

Friday, May 31, 2019

Helping Doesn’t Always Help

My programming students are working on their final/semester projects. As is typical some of them are doing extra work on their projects at home. Normally that is pretty great. They get better projects and they learn that they can continue learning and coding on their own. Some students get help from parents. We’re in a pretty high tech area and lots of parents are software professionals.

I don’t blame parents for helping. Parents are a students first and best teachers. Most times parents work within the scope of what their students are learning in school and do a good job of explaining what they are showing. But occasionally we see some code that really begs for a discussion with the student to see if they actually understand the code they are using.

Usually the clue is that the code includes features that are not covered in class. The Ternary operator ( ?: ) in C-family languages for example. This is not something we really have time for in a single semester first programming course. It’s pretty cool and really useful in the right circumstances but it can be an extra cognitive load for beginners.

Again, teaching this operator is a great thing. Having a student include it in their code without understanding it is another thing completely.

It’s not just parents that do this. Students do it even more often. One student discovers something cool or useful and shares it with others. The first student usually has a pretty good handle on it but don’t always do a good job of helping the other student understand it. Students, like the parents I see helping, mean well.

It drives teachers crazy though because it makes it hard to tell what a student understand and what they included just because someone told them it would solve their problem. This is one reason I still do quizzes and plan to do more next year.

Society tells students that the result – a good grade – is the important thing. For many students, and a few too many parents, grades and learning are independent. Teachers mostly see their job as teaching and not grading. It would be easy to just give everyone an A and make them happy. In the long run though we wouldn’t be doing anyone any favors.

Wednesday, May 29, 2019

Learning From Today and Planning For Tomorrow

It’s the end of the school year for me. Next week is our final exam week and my students are working on their semester projects. I use projects rather than an exam because I think students learn more from projects. Writing an exam would be easier in some ways but I am more about learning than grading. It seems like my students are learning a lot. Many of them are really grokking how to put all the concepts we have been learning together for the first time. Others are stretching themselves to learn new concepts beyond what I taught in class. And I’m seeing some new (to me) ways of addressing old (to me) problems. It’s win win.

Semester projects reminds me in a serious way that diversity of thought, of looking at a problem, and at putting tools together is really important. I’ve gotten a couple of new design patterns to add to my toolbox that were driven by students seeing different ways to do things. This is not unusual. It seems like every semester I learn something new from my students. Sometimes it is errors I have never seen before and sometimes it is new ways of solving problems but it is all good. It’s never the same course twice.

And that brings me to planning for next year. I created a number of new demonstrations this year. Some worked great. Some not as well. I’ll spend time evaluating them this summer. I’ll also spend some time thinking about new projects for next year. It is difficult to find the time to come up with new things during the school year. There is too much grading, adjusting the schedule to match what is going on in school, and just plain teaching. And maybe I’ll record some short talks or demos to make available to my students for review.

While I am mainly a project oriented person I have seen some value in quizzes for formative evaluations. They are faster for one thing. And they help determine who really gets the concept and who is getting a bit more peer assistance on projects than they really should. So I plan to write a bunch of them over the summer. Not full period exams but 15 minute quizzes. Automated grading speeds things up and I am finding that the tools for seeing what questions are gotten wrong and correct is helpful to me.

I’ve got a good bit of work planned for the summer. I’m also attending ISTE and the annual CSTA conference. I expect both of them to provide me with some new ideas to incorporating into my teaching next year. If you’re at either of these conferences I hope you’ll look me up. I love connecting in real life with other teachers.

I also hope to learn some new things this summer. I’ve ordered a copy of GitHub For Dummies. I figure it is about time I learned GitHub. Maybe I will use it with students. I think that would be very valuable for them but it depends on me learning enough to get them started. I plan to continue trying to figure out how to format apps for my Android phone using Xamarin and Visual Studio. Code is easy (C# for the win) but the UI APIs are a bit more of a learning curve. I’m not planning on using it with students right now but I want to write my own apps for me.

SO what are your summer professional development plans?

Friday, May 17, 2019

ACM CompEd Conference

Brett Becker has been blogging about the ACM CompEd conference now taking place in China. See his blog post at ACM CompEd daily update 1: Day 1 for example.  Looks to be a great conference. Not a lot of high school teachers have travel budget to attend of course and a lot of us are wrapping up the school year so it would be hard to get away anyway. But there is good news.

On his post you will find a link to the ACM Digital Library where the conference proceedings are currently open.

Reading the papers is not quite as good as hearing the talks but it is a lot better than missing out completely. There are things of interest to middle and high school teachers as well as some papers about integrating CS into other subjects. Like I said, things to a wide range of CS education interests.

I've downloaded about 18 papers to read. Hopefully once the school year is over in a couple of weeks I'll be able to give them the right amount of attention. But grab them now as they will not be available to people without a subscription to the ACM digital library for long!

Thursday, May 16, 2019

Computer Science And x

For most of my teaching career I have been focused on teaching computer science in stand alone computer science classes. And  I really like teaching computer science as a standalone class. But lately I have been thinking more about where CS can/should fit into the greater education process. This is not completely new thinking for me. I’ve always thought that computing tools are great for teaching other disciplines.

Spreadsheets are awesome for dealing with data in science classes, math classes, and even social studies (think graphing population growth) for example. Even early in my teaching time I said that there is a time for teaching tools to learn the tool but eventually using the tool to learn other things is or should be the goal.

We teaching reading as an independent subject in the early years but over time it become less an independent subject and more a tool for learning other things. The same is largely true of mathematics.  I believe that computer science in academia will be at its best when we reach a point where it is more and more a tool for learning other subjects.

CS teachers like to believe that somehow the knowledge and problem solving schools in CS transfer magically to other disciplines. Research show that any transfer is minimal at best. We in computer science have to stop ignoring that research is we really want to add value to education. Helping teachers on other disciplines learn to use CS in their teaching has to be part of that.

Mark Guzdial, who has taught me more about how to teach computer science than any other individual, is focusing his current research on to help teachers in other disciplines integrate computing into their teaching. This is important research in my not so humble opinion. I think that a lot of us who are already teaching CS need to start thinking about this as well.

At one point I thought technology integration specialists would carry this load. Many of these people are computer science people but many more are not. SO far I see computer science being integrated across the curriculum mostly in elementary and some middle schools. I really admire the K-8 teachers who have taken on the task of learning CS, largely on their own, and finding ways to incorporate it in to their teaching. There is little if any room for an independent CS course in elementary schools. There is a bit more in middle schools but the time is limited in most of them.

I don’t see much work on integrating CS in high school courses. The Physics department at my school would like to see us teach Python as they are seeing more of that in use by physicists. That my be an opening and we may add Python to our program at some point. Change is slow in education. Even sometimes in computer science.

Still, change has to happen. Change has to happen not just in standalone courses but who computer science departments in schools support other departments. For transfer of skills and knowledge to transfer it has to have context. And context doesn’t just happen. We have to make it happen.

PS: I really should have included this from the start. Bootstrap has courses aimed at algebra, statistics, business, social studies, science AND physics. GO check it out. It’s the sort of thing we really need.

Saturday, May 04, 2019

Migrating to Android–an early trip report

One of the reasons I held on to my Windows Phone as long as I did is that it was so easy to program apps for it. I had come to depend on one particular app I wrote to help with with the rotating schedule we run where I teach. I finally gave it (too many apps I could not run on the Windows Phone) and got a Google Pixel. Programming an iPhone would mean I also have to buy a Mac and that was a bridge far to far for me. Of course the first thing I wanted to do was to migrate my app to the Android platform. Visual Studio, Xamarin, and C# seemed the way to go.

The code and logic moved almost transparently. The user interface not so much.

One thing that complicates things is that the tools change so quickly. UI code that I created with Visual Studio 2019 Preview seems different from what was created by Visual Studio 2017. This also means that a lot of videos and tutorials are already aged out of usefulness for me. I’m still looking for some videos that work both with beginners to the Android API and Visual Studio 2019.

I finally got something working. It’s ugly but it works. The next step is to learn how to do decent screen design with the Android API. It is not as intuitive as Windows Forms was/is. Not even close. I feel like I am back in the 1980s. It feels like we are regressing in making user interface programming.

At least we still separate form and function. As long as the UI objects have the same names all my C# code seems to work quite nicely. This wasn’t the case in the 1970s and early 1980s. Back then UI code was usually integral with the logic code. That changed over time and the idea of separating form and function moved from new to controversial to the way things were done. It’s the idea that lead to front end and back end developers. But I digress.

Being able to drag objects where ever I want them is a wonderful thing about Windows Forms Design. Microsoft seems to be moving away from that easy to use tool to making programmers write more code by hand. I’m not a fan. Like I said, a return to the distant past.

At this point I have confirmed that coding Android apps is easy and all my C# knowledge is still usable. I’ve also confirmed that I have a lot to learn about creating an Android UI. I’m starting to look for a good book or some up to date videos that are not just marketing demos. Marketing videos focus on showing off features rather than teaching. Teaching videos are a completely different emphasis.

Anyone want to recommend a book or a set of videos that worked for them?

Wednesday, May 01, 2019

With Great Code Comes Great Responsibility

Omidyar Network, Mozilla, Schmidt Futures, and Craig Newmark Philanthropies recently announced the winners of the Responsible Computer Science Challenge. The challenge, and grants of up to $150,000, go to universities but the programs might have some use in high schools. Maybe. At some point.

The winners’ proposed curricula are novel: They include in-class role-playing games to explore the impact of technology on society. They embed philosophy experts and social scientists in computer science classes. They feature “red teams” that probe students’ projects for possible negative societal impacts. And they have computer science students partner with local nonprofits and government agencies.

Of course it is wonderful that these universities are integrating ethics into their courses. Society will benefit more as these universities package, promote, and see their programs expanded into other universities. That is the goal of the Responsible Computer Science Challenge. There is a second round of grants with that as the prime goal. It makes sense to develop and test programs before expanding them.

I hope that these institutions will seriously consider helping to adapt these programs, tools, methods, and other resources so that they can be incorporated in high school (maybe even lower grades) in the future.

Responsible Computer Science Challenge banner with logos

Monday, April 29, 2019

Game of Thrones and Computer Science

I confess that I have not watched a single episode of Game of Thrones.  That doesn’t mean I am oblivious to the social impact of the show. My online social media is full of it. So when Rita Tillson Vasak linked to this Slate article explaining why a recent episode was so hard to view I jumped to read it. The article talks about data compression and how a lot of compression made it hard for a lot of people to really view the scenes.

It talks about data compression in a way that assumes the reader has a clue as to what they are talking about. It uses the term “lossy video compression” and talks about the layers of compression involved in getting the digital image to your screen. I wonder how many people read that article without comprehending it very well. Hopefully my Advanced Placement Computer Science Principles students would get it all.

We talk about compression in AP CS P. I’ve also played with lossy compression with my Programming Honors students (Lossy Text Compression Project ). I talk about compression in terms of text, images, video, and music. I think students mostly get it.

Rita suggested this article as part of review for the APCSP exam (coming in less than two weeks!) and I think that is a great suggestion. I may use it next year when we talk about compression as well. I think it is a good visual and discussion as to what can go wrong in our attempts to get the most data through the smallest “pipe” in the least amount of time.

Showing specific examples of the effects, positive and negative, of computer science technology when it also ties into a social event can make a great impression.

Sunday, April 21, 2019

More Than One Way To Code a Solution (to a programming project)

Garth Flint has an interesting post about grading programming projects (It is never easy) in which he talks about the interesting solutions students come up with. It struck a cord with me on a couple of levels. Yes, it makes grading more difficult but it also means that students are thinking for themselves.  Or so I chose to believe. Sure some of them look up solutions on the internet but they have to understand them well enough to explain them and make them their own.

I figure that on average a class full of students will come up with three different ways of doing things. Sometimes only two but sometimes more than three. Sometimes I will take samples of the various solutions (with no names) and discuss them with the class. It gives me a chance to show that there is more than one way to do things AND to discuss optimization a little bit.

Occasionally students have come up with solutions that I had never thought of and were even better than how I had done it. I love it when that happens. I love new solutions. To it also emphasizes the value of a diverse group of people looking at a problem.

As Garth mentioned in his post, student ideas move quickly through a computer lab.  I struggle with that a bit. How much help is too much help? Where is the line between “he helped me with it” and “I copied it from her?” And how do you tell where the students are around that line? I could get pretty fanatical about it. I’m not sure how productive that is though. It probably adds as much stress on me as it does for students. I toss in quizzes as well and students who understand what they are doing do a lot better on then than students of get too much “help” with their projects. Using multiple forms of evaluation is a good practice anyway I’ve been told.

Generally I see projects as more effective as a learning experience than as an evaluative tool. Sure they help evaluate learning but a practice, an exploration of ideas, and a way to learn things is their highest value. If students come up with implementations differently for what I would come up with I see that as a learning win.

Thursday, April 18, 2019

What is in a name?

It’s been said that the three hardest things in programming are naming things and off by one errors. For some reason, this semester, my students are having the most trouble with naming things. Specifically, they seem to have trouble making the connection between names and objects.

For example, they will use the name of what looks like a text box but without actually instantiating the text box firs Or they will use a different name for the textbox than the name the textbox actually has. And they’ll be surprised at getting an error message that says “the name ‘x’ does not exist in the current context.” The same is true with undeclared variables. Often this is caused by not paying attention. I will set the name of an object while live coding and then use that name later in the code. If they were not paying attention any of the three times I point out the name declaration they may not use the same name in their own code but expect it to work later. After all, it worked when Mr. Thompson did it.

Now of course I have explained all of this numerous times. I think many times students are just expecting the system to fill in the blanks for them. It would be nice if the system would. Maybe one day we’ll have artificial intelligence built into development environments that will help with this sort of thing. But we are not there yet.

Our IDEs do a lot for us (developers) that they didn’t do for us back in the day. No autocorrect in punch cards. I know that some educators believe that using a fancy IDE with automatic features is a bad idea. Students should learn without them. They may have something of a point but I resist the idea because I don’t want to make programming to hard. I don’t run a weed out course. Plus these modern tools open the door for students to experiment. Intellisence in Visual Studio lets students see a lot more options then I have time to cover in class.

I keep coming back to naming things though. Selecting meaningful names is important. Making the connection between declaring and defining objects/variables and the names themselves is important.

Spring break started tonight. Figuring out how to address this is something to think on in a couple of days when I’m relaxed.

Monday, April 08, 2019

Teach Programming or Teach a Programming Language

For me, teaching is all about the concepts. Programming languages change. My first programming language was FORTRAN. This was the big language with I was in university. Today? Not so much. But loops and decision structures still exist. Over my career, I have learned a bunch of programming languages. I’m not sure I want to know how many but its a lot.

This morning I was reading Mark Guzdial’s blog as one does (Why we should explore more than one programming language across the curriculum) which comes as I am looking hard at my school’s computer science curriculum.  We teach several programming languages. Visual Basic in our freshmen course, App Inventor for our mobile app development course, C# in honors programming, JavaScript in AP CS Principles, and Java in AP CS A. SO potentially students can learn a bunch of languages during their time here.

Is this good or bad? Are there too many languages? Are these even the right languages? I believe that much is dependent on ones goals. Is our goal (in HS CS) to teach a programming language or to teach how to program (programming concepts).

As I started off this post, I believe that in the real world people who develop software, professionally or other wise, will need to learn new languages as time goes on. Mark has been writing a lot about task-specific languages (Task-specific programming languages: People aren’t dumb. Programming is hard.) and it is pretty clear to me that is a coming thing.

Teaching all programming classes using one programming language is probably a great way to teach that language but to quote Mark’s blog “We have no evidence currently that language-specific programming knowledge will transfer” So how do we prepare students who will have to learn new languages for new tasks?

Someone once said that the second programming language is the hardest one to learn. I can see how that could be the case. On the other hand learning programming languages does seem to get easier after that second one. I believe it is because learning a second language forces one to think beyond the syntax.

In one class, some years ago, I started showing my AP students who to do the same loop in a number of languages, including assembly language, and one student claimed later that was the most valuable lesson of the course. I still try to show multiple languages at times but since most of our students have already been exposed to several by the time they get to Advanced Placement that seems less necessary today.

Still I toy with the idea of writing a parallel programming book using several languages.  This is an idea borrowed from parallel translation Bibles where several translations of the Bible appear side by side on the page. A great study tool for religion that might work in programming as well.

Coming back to goals, I can see teaching a lot about one and only programming language as a somewhat reasonable way to prepare for a job but not for a career. I still remember getting my first programming job because I knew one language pretty well. Six months later I was handed a project specification and a language reference manual for a language I had never heard of and told “go to it.”

I truly believe that having a background in multiple languages was the difference between success and failure for me.

Friday, March 22, 2019

Debugging Student Code for Fun and Learning

Students are really good at creating strange hard to solve bugs in their code. I am convinced that the code of a raw beginner can easily be harder to debug than that of a professional coder.

I had a couple of good ones today. One was actually pretty easy once I realized the cause. I have some international students. Great kids, very smart, hard workers. English is not their first language though. In fact, English letters are not their first character set. In one class I have boys from Cambodia and Viet Nam. The character sets they grew up with are very different from English characters. This means that sometimes English characters confuse them. l, I and 1 can all look alike to them especially in some fonts. Like this one. So I had some non obvious "spelling errors." They and I have a better idea of what to look for next time.

The other one was harder. We’re using C# and Windows Forms. Now normally this makes things easy. But you can also cause some very puzzling errors. In this case, the code seemed to be doing everything it was supposed to do EXCEPT showing the results in a list box. I tried a lot of my bag of tricks. Single stepping through code, displaying intermediate results (that didn’t work because nothing was displaying in the list box). I copied the code into a new project. I created new objects. I tried a lot of things.

Finally, I did a side by side comparison with a project that worked and that showed me the problem. For the curious, Windows Forms projects run a subroutine to initialize and instantiate the objects on the form. Some how, probably a copy paste error, this student was calling it twice. Without going into detail, this resulted in two sets of objects with one of them covering the set that was actually being acted upon for the display.

I try to look on the bright side of things. In this case, I have new things to look for that I didn’t have before, I have gained insight into issues that my international students have (and may change some variable names I use), and I got to demonstrate debugging techniques to some students. That’s a win right?

Tuesday, March 19, 2019

Interesting Links for Computer Science Educators 19 March 2019

I haven’t done one of these for a while. I still Tweet or retweet a lot at @AlfredTwo but I needed a break. I’m not sure I will do this every week but I think I will shoot to do it from time to time.

Microsoft Education posted a bunch of resources on Ways to encourage girls to keep pursuing STEM this Women’s History Month There are some posters I think will show up in my computer lab soon there as well as other helpful links.

David Renton is doing some amazing things with his students who are programming virtual reality applications. Currently he is having Students Build International VR Prototypes for Children This is more than about computing. It is a multi-national effort with some support from Microsoft in the UK and deployment at a hospital in Sweden.

Mike Zamansky has a  great post about Adapting A Nifty Assignment  You may or may not be familiar with the SIGCSE Nifty Assignments sessions, check them out if not, but they are pretty nifty but many of them really do benefit from adaptation to a particular environment.

I found this on the Blog at CACM I don’t know about you but calculating with Roman numerals (what no zero?) was something I wondered about. This article explains it all. I wonder if this might make a nifty project? Calculating With Roman Numerals is Not So Difficult 

Speaking of SIGCSE, Bryan Twarek provides a nice list of K-12 Teacher Takeaways from SIGCSE 2019  on the CSTA Blog. Not as good as being there but Brian includes a bunch of related links.

Under my list of things to keep an eye on, Microsoft had a post called Achieve more with Microsoft Game Stack It looks mostly like a repackaging or rebranding of a number of new and existing resources for game developers. Will it have application for schools? Maybe in game development courses but even there it seems like Game Stack is more for professionals than beginners. But we’ll see if anyone in education takes it on and provides information.

Thursday, March 14, 2019

Awards I Wish We Didn’t Need

Last week my school was told we had earned the College Board’s Female Diversity award for both Advanced Placement Computer Science A and Advanced Placement Computer Science Principles based on how many female students we had in those courses last school year. Yeah!

We’re one of two schools in the state to get this recognition. That’s a bit disappointing. The more I thought about it the more I thought how sad that getting to adequate female representation was so rare that schools were getting special recognition for it. Are there similar awards for other AP courses? Are their awards for schools for getting to Male Diversity numbers in courses were male students are underrepresented? Is that even a thing?

Don’t get me wrong. I am thrilled that we have good representation of female students in our AP CS courses. And I’m not shy about sharing news of the College Board's recognition. 

It’s hard to get solid APCS enrolment period. I teach at a private Catholic school that requires four full years of religion. That has a serious impact on electives. We have even better female representation in our lower level CS courses because we require a full year of CS for graduation. AP CS is going to be an elective so we have to have a good environment to get students to want to fit it in.

With cultural norms the way there are, a lot of female students are encouraged to follow other academic paths. World languages, for example, fit the stereotype and it often feels like that is a more common, if not natural, path for female students. And the boys seem to be less excited about languages.

Our goal at my school is to ensure that all students are comfortable and feel like they belong in computer science courses. We are careful about room decorations. You’ll see women in computing highlighted in posters and bulletin board items for example. I think the most effective effort it that teachers encourage all students, reassure them that they mistakes they make don’t mean they are stupid or incapable, and include projects that are not gender biased. You know, be a good teacher.

For now we all need to make efforts to include a more diverse set of students. And it is nice to be recognized for the success of those efforts. But I’ll tell you, having a diverse group of students is all the reward I really need.

Tuesday, March 12, 2019

High School CS Education: Where Do We Start and Where Do We Go?

There are a number of sets of standards with most based on the CSTA standards ( and the K-12 CS Framework ( A lot of really smart people (and me in the case of the framework) worked on them but I've been thinking about creating my own set to use.

Why? Difficult to explain but in large part to get things clear in my own head. What do I see as the concepts and ideas I should be teaching in my high school? How do I want to express my thoughts – the same as the existing standard or will putting them in my own words help me understand them better? An open question.

Now one might think this is easy with the standards already written. But it is more complicated than that. High school is very much in the middle for computer science. We’re not yet college/university but we want students to be prepared for that level of education. At the same time, there is no standard of knowledge that universities are expecting all incoming students to have. That makes their lives difficult but they have been living with that as long as there have been CS courses. It’s leaves us in high school a little more free to determine our own output goals though.

On the other end, there is no standard set of CS knowledge that high schools can expect all students to have. That is especially true for a school like mine that takes in students from over a score of different middle schools and two different states. Like the universities, our curriculum has to start assuming no background at all. Oh sure students are somewhat tech savvy compared to many of their parents but I still spend time teaching how to move files from one folder to another. Being great with Instagram doesn’t translate to computer science knowledge.

We see some students who come in more advanced as well. They may have done a lot of programming in middle school. Many in an enrichment course, a summer program, or FIRST Lego League or some other opportunity. They may even be programming in higher level languages. Can they skip the first course? Sure, as long as we have something more advanced to help them continue to grow and learn. It would be a shame if they were effectively done before high school and spent 4 years forgetting things before university.

As I think about high school computer science curriculum holistically I think about the Computer Science Curricula 2013 (CS2013) document. One key take away for me there was the three levels for university curriculum. Basically it was things all CS departments should offer, a level that all departments should offer “all or almost all”  and electives. For high school I don’t know that I want three levels. Maybe two would be enough. Things that all high school curriculum should offer and electives. Earlier version of the CS Curricula had only two levels. I am not sure there is room in the schedule for three levels in high school. Electives should be offered in schools where there is more room.

I hesitate to specify standard or required or even recommended electives for high schools. Gradually CS, and other subjects, move down from universities but there is no clear vision for what will move down from universities to high schools in the near future.
An other idea I like from the CS 2013 document in the Knowledge Area breakdown of concepts. This sort of breakdown is also included in the CSTA Standards of course. Do I want to come up with my own breakdown or use the CSTA version? I’m undecided.

Seems like a big task and it is. But I really feel like I need an expression of my personal (well researched and thought out) ideas of what should be taught. Anyone else feel like this?

[Note: I was on the CS 2013 ACM/IEEE Task Force and the K12 CS Framework writing team. And I still think I need to think about this stuff.]

Monday, March 11, 2019

Don’t Cross The Data Types

Remember in the first Ghostbusters movie where the ghostbusters are told not to cross the stream of their ghost busting guns? And then at the end they do cross the streams? Mixing data types is like that some times. You really have to know what you are doing when you mix data types.

The Facebook group for AP CS A teachers recently had this Java example:

Can anyone explain why a + b is NaN but a+=b is zero?
int a = 0;
int x = 0, y = 0;
double b = (double)x/y;
System.out.println("a: "+ a);
System.out.println("b: "+ b);
System.out.println("a + b: "+(a+b));
a += b;
System.out.println("a(2): " + a);


a: 0
b: NaN
a + b: NaN
a(2): 0

NaN is not a number and is the result of the divide by zero. You probably shouldn’t do that anyway but it happens. What is interesting here is the different way that (a + b) is handled compared to a += b

a += b does a conversion of b to integer before it does the addition while (a + b) does a conversion of a to double. That explains the different results. Of course if you were to do a = (a + b) you would probably get a compiler complaint. I think. I know you would in C# but I haven’t tried Java yet. FWIW C# also complains about a += b and demands an explicit cast. Different languages and compilers handle these things differently.

So what is the message here? I think the message is that programmers should usually make explicit casts when they mix variable types. Maybe you know what will be cast to what for different variable types and different operations but a) how much do you want to bet you’re right and b) how much to you want to bet that the next person to look at your code will understand what is going on behind the scenes?

Mixing types causes a lot of confusion for beginners. SO does how numbers are stored (some kids never seem to understand that 0.1 is an infinitely repeating fraction in binary and what that means) of course. Encouraging students to cast or at least to be very careful about the types they use and the types they mix is an important lesson.

Friday, March 08, 2019

Making Projects More Interesting With More Data

My students are working on the palindrome project. You probably know it – enter a string and report if it is a palindrome or not. In my case, I have them create a method to “clean” the string by stripping out all of the characters that are not letters and a second method to reverse the string. My goal is practice in creating methods as well as string handling and loops.

It’s always more interesting if the test data is more interesting. There are lots of common palindromes that students are familiar with such as “Madam I’m Adam” and “Race Car” and the ever popular “Mom”, “Dad”, and “Bob.” My favorite is “A man, a Plan, a Canal – Panama” because you can read it dramatically. This week I stumbled on a web site dedicated to palindromes - There are probably other palindrome related web sites as well.

I’m thinking about supplying a file with lines that are and are not palindromes and having students modify this first program to read the file and report.  More data is better data.

Another idea I have percolating is asking students to write code that creates palindromes. I’m not sure how hard this would be as I’m still thinking about how I would do it. Again, data is important. You want to use real words and ideally the phrase should make sense. Does it have to though? Hum.

I have a dictionary file – a text file with almost 114,000 words in it. I figure that should be useful for something. I keep thinking it would be useful for a lot of interesting projects – things like word games (Boggle, Scrabble, etc.)  or maybe spell checkers.

There are sources of large text files on the internet as well. I have files with the full text of some books (in the public domain of course) and Shakespeare's sonnets. Check out Project Gutenberg which has some 58,000 public domain books

I’m thinking some interesting word and letter count projects are a natural. A lot of the projects that have been presented at the SIGCSE Nifty Assignments session (collected here at involve working with data sets of words or text. You all know about the Nifty Projects resource right?

You can also make interesting data. For a long time I have assigned a project that creates driver’s licenses based on name and birthday. New Hampshire recently moved away from this scheme for privacy reasons but it was/is a fun project. I grabbed first and last name data from the Census Bureau (there are other lists) and wrote a program to create a data file of random names and birthdays. I’m toying with assigning something like that as an assignment some day. Making sure the dates exist (no February 30th for example) makes it fun. OK, harder, but harder is fun right?

What sorts/sources of data do you use to make projects more interesting?

Monday, March 04, 2019

Remember The Ladies–And Act

In March of 1776, Abigail Adams wrote to her husband who would be the second US president “I long to hear that you have declared an independency. And, by the way, in the new code of laws which I suppose it will be necessary for you to make, I desire you would remember the ladies and be more generous and favorable to them than your ancestors. Do not put such unlimited power into the hands of the husbands. Remember, all men would be tyrants if they could. If particular care and attention is not paid to the ladies, we are determined to foment a rebellion, and will not hold ourselves bound by any laws in which we have no voice or representation.” [ emphasis mine]

After all this time, we, mostly us men, seem to forget the ladies. Most of us are aware that there is a shortage or at least an imbalance of women in the computing field. It’s men’s fault mostly.  We make it worse when we ignore the efforts and accomplishments on the many wonderful women in our field.

We talk about Ada Lovelace and Grace Hopper but use them as tokens too much of the time. Today there are a number of wonderful groups whose focus is directly on bringing more women and underserved minorities into the computing field. Unfortunately, they don’t get the attention they deserve.

Reshma Saujani, founder and CEO or Girls Who Code gives an important response to this problem with her post Erasing Women in Tech: How 60 Minutes Ignored Women’s Voices, Stories, and Expertise

Now I can hear someone saying, well, yeah, but is doing great work and they are helping girls and young women. Plus the 60 Minutes piece was a good promotion of computing for all. There is some truth to that but it misses a point.

These other great efforts, those that Ms. Saujani names and more need their own recognition. How else are they going to attract the participants, the supporters, the money, and build sustainability if no one knows they are out there? Outstanding programs like these need the sun shown on them so they can grow and thrive.

The truth is that we need some special programs for girls and minorities because the male dominated organizations are still not making them as comfortable as they should. Oh sure some of us are trying. I like to think my classrooms are safe spaces for everyone. I’m sure most of my regular readers feel the same way about their classrooms and computer labs. We may even be right. But we’re not everywhere.

As a community, we in computing have to be more generous and favorable to women than we have in our more recent history. Our future depends on it.

Wednesday, February 27, 2019

What Are You Reading?

We all get asked this question – What are you reading? Often this is the context of an interview and the person asking is really asking “how are you keeping current in your field?” For computer science educators there are few things better to read than SIGCSE papers. Right now the Proceedings of the 50th ACM Technical Symposium on Computer Science Education are open for download. I think they’re only open (FREE) to non-members for a few more days. The conference closes this Saturday.

I’ve been downloading anything and everything that looks interesting or useful to me as a high school CS teacher and as someone interested in learning more about the field. I have about 35 papers downloaded. It’s going to take me a while to read them all.

I am a member of ACM and SIGCSE so I will be getting these papers in hard copy so you might wonder why I am downloading PDFs. The short answer is that I lose paper documents but I have a lot of room to store soft copy. And I confess that I want to start reading now.

I can’t make it to SIGCSE (it started today BTW) but I will be following Tweets and other social media updates. Having the papers available will help me understand what is going on better.

So are you taking advantage of paywall free access to SIGCSE proceedings? What other places do you go to learn what others are doing?

Tuesday, February 26, 2019

CSTA Board Elections 2019

Wow! Computer Science Teachers Association members should all have gotten an email about this year’s election for the CSTA Board. It is a remarkable slate of candidates. It seems to get stronger year after year. We, members, have to make decisions though. Not that anyone really cares but I am sharing my thoughts.

The K-12 seat is between Doug Bergman and Art Lopez. I’m sure Art would do a great job but I’m voting for Doug Bergman. I’ve know Doug for years and pushed him to run for the Board for several years before I got him to throw his hat in the ring. I’ve been impressed with his performance over his first term on the Board. He is a tireless worker, a leading edge teacher, and a strong promoter of computer science education. Doug gets things done.  Doug Bergman has earned a second term on the Board.

K-8 has another good pair of candidates - Vicky Sedgwick and Alana Robinson. Coming from a big city system and a special education background is a strong plus for Alana. On the other hand, Vicky has been a remarkable advocate for K-8 teachers inside and outside CSTA. Her work with the #CSK8 Twitter chat has been a phenomenal community builder and educational experience for K-8 teachers everywhere.  I would like to see Vicky Sedgwick have another term on the CSTA Board.

School District representative is also a tough choice. Dan Blier and Byran Twarek. I met Bryan while working on the K-12 CS Framework and was very impressed with his work ethic and commitment to computer science education. His experience and performance on the board suggest that Byran Twarek should have a second term.

At-Large is the toughest decision. There is no incumbent nominated for one thing. And both candidates are seriously strong. Lien Diaz has done a lot of work growing computer science education both at her time with the College Board and since moving to Georgia Tech. She’s smart and understands the sort of politics that are involved in growing CS education. Michelle Friend was very important to the creating and early years of CSTA.  Her institutional knowledge of CSTA is very valuable.

I’m still thinking about this one and hate not to vote for Michelle but am leaning towards Lien Diaz.

[Full disclosure: I suggested myself as a nominee for the At-Large opening. I don’t doubt that either of the nominated candidates will do as well or better than I would.]

OK people. My two cents are out there. The CSTA Board candidate bios are available. Read them critically and make your own decision. Agree or disagree feel free to add you two cents in the comments.

Friday, February 22, 2019

Don’t Trust Algorithms You Can’t Read

I admit that I am a sucker for “the best [what ever] in each state” lists. I want to see how many I have visited and what is “the best” in my state. Most of these are based on someone’s personal opinion but others are based on some sort of data and an algorithm.  I think most people are aware of bias in the subjective lists and take them with a grain of salt. It is tempting to look at lists based on data and computer algorithms and more accurate though. I mean, look, it is supported by data!

The most recent example of this was a list of the most boring towns in every state. I was sure the town I live in had a short at that one. There is nothing to do. One country store is the only retail operation I know of in town. There are no attractions, unless you count the beehive hut or maybe our historic meeting house. We didn’t make the cut though.

The town that did make the cut for New Hampshire was Bartlett. Now Bartlett has an outstanding ski resort, Attitash, an amusement park, Storyland, and a lot of good places to eat. There is a lot to do in Bartlett. It is anything but a boring place.

The problem, of course, is the data selected for the algorithm. They based their decision in large part on average age and population density. My observation is that a lot of resort areas, which are almost by definition not boring, have low full-time population densities and older permanent residents. Now they also look at “things to do” but it is far from clear where they get that data.

Choosing the right data is part and parcel to getting a good result for any sort of algorithm. This is why transparency of data and algorithms is important in evaluating any conclusion.  This is an important concept for our students to understand. To me it is as much a computing topic as it is a societal topic. As we get more and more data and more and more people try to make sense of the data we have to understand that just because there is data in to an algorithm and a result coming out that is not enough.

I haven’t heard it said much recently but we used to say it a lot.

Garbage in, garbage out!

Friday, February 15, 2019

Minecraft Curriculum for Teaching Computer Science

I'm not a Minecraft person. I've had the demos. I know that some kids really get into it but … Well, some teachers love it as much as the students. For them it’s probably a great thing if there was some curriculum to use with it.

So, if you do like it and you think it would be motivating to teach computer science using Minecraft for Education there is new Computer Science Curriculum From Minecraft

Thursday, February 14, 2019

US Department of Education Needs CS Experts as Reviewers

I recieved this from Pat Yongpradit of and thought I should share it.

The US Department of Education has announced the EIR grant competition for FY 2019. This year EIR incorporates an exclusive priority for computer science with a focus on increasing diversity and equity in access, as compared to last year where the highlight was that CS was merged with STEM as a combined priority. See more detail in our blog.

There are many moving parts to the federal grant review and award process, including a merit-based review process. In order to adequately score grants featuring computer science, the US Department of Education must have enough reviewers with K-12 computer science education experience. There is more information on the merit-review process and the Department’s mechanism for selecting reviewers in this blog. has been asked to put interested folks in touch with leaders of the EIR grant program. If interested, please send your CV to

Having CS knowledgeable reviewers participating in the federal grant review process is crucial to maximizing the opportunity these grants present the field and our collective goal of expanding access to K-12 computer science.

Monday, February 11, 2019

Programming Has Sure Changed

Last week, I was reading some old code. I wrote it in 1975. It was in FORTRAN IV and it was on punch cards. Really bad code. One character, meaningless variable names. Lots of goto statements. FORTRAN IV didn't have while loops but you could get the same thing with goto if done right.

Someone is probably going to argue that if there are goto statements its not right but it was the only way back in the day.  The famous “GOTO considered harmful” paper had  been written but not universally accepted yet. FORTRAN IV had not adopted language features to make it easy yet.

While I was in university the big new thing was called structured programming. It required some new ways of design and eventually some new programming language features. It took the tools in the languages changed before we could get by without that nasty goto statement.

FWIW I’ve written new version of this program in other languages since and it is much easier, cleaner, self-documenting, and just better across the board with new languages, libraries, and programming paradigms. The basic algorithm is the same though.

The big surprise in my old program was that is was extremely well commented.  The first time I tried to replicate that program in a new language revisiting those comments saved me a lot of time  In fact, one could easily rewrite it in a new language from the comments alone. I could at least feel good about that.

Latter in my career, object oriented programming was the thing. That also required new design considerations and programming language features. FORTRAN IV could not have supported OOP. Today there are versions of FORTRAN (and COBOL too) that have language support for object oriented programming. I’m not sure I want to see them though. Just saying.

I’ve been thinking about what this means for how I teach students today. The rate of change in computing and programming is growing not slowing down. As much as things have changed in the last 45 years they are likely to change even more in the next 45 years.

Some concepts are likely to be around forever. Decisions are likely to rely on Boolean expressions. Repetition is likely to stick around and require proper set up, values to change, and code to check for completion.  We’re going to be thinking about memory and data types even if we don’t think about them in exactly the same way.

John Ruskin said, "For all books are divisible into two classes, the books of the hour, and the books of all time." I first saw that on the library wall when I was in university. The same is likely true if we substitute some software design concepts. Just as monolithic programs gave way to structured programming and structured programming gave way to object oriented programming, programming paradigms change based on changes to language, hardware, and the needs of the day. I don’t really know what changes we will see with quantum programming for example.

What ever programming language we teach with though we need to think about the concepts, especially foundational concepts, that are likely to be around for the long term. I haven’t programmed in FORTRAN IV in decades but understanding how those horrible goto statements mixed with line numbers and if statements worked sure made understanding a modern while loop easy.

Thursday, February 07, 2019

Programming Projects and the Good Idea Fairy

I think Garth Flint (blog at Garth's CS Education Blog) first introduced me to the idea of the good idea fairy. The good idea fairy strikes you with a great idea that works out well (most of the time) but takes you more time to deal with than you first expect. That is probably why you take the idea in the first place.

Well, last semester the good idea fairy visited the idea of a Pez dispenser object  when I was teaching creating of classes and objects in my honors programming class. The implementation was horrible but it did seem to help as one more example. Follow up to a few days ago and the new call for proposals for the annual CSTA conference. What do I have that is a nifty project? I’m still trying to decide what might qualify but the good idea fairy smacked me with the Pez project.

Even before I looked at the old project and realized how bad it was the good idea fairy suggested that a Pez dispenser project really should use a stack object. Well, duh! I and others have been using a Pez dispenser as an example of a stack for years. So that is what I have been working on lately.

I need a Pez candy class first. I think that will be easy for students to design. The data is simple and the methods are few. Then we can design the dispenser class. I think it will be interesting to see how different students design these classes from how I have been thinking about them. I’ll be disappointed if I don’t learn something from them or at least get some ideas for other methods and properties.

I’m constantly trying to think of new projects and improve existing projects. Finding projects that students can relate to, that they can have fun with, and that can really teach to concepts is a never ending task. It’s a task I love though. Wouldn’t it be horrible to teach the same projects year after year? Thank goodness for visits from the good idea fairy.