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.

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?

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!

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.

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?

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.

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.

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.

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.

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.

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?

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.

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.

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 (https://www.csteachers.org/general/custom.asp?page=standards) and the K-12 CS Framework (https://k12cs.org/). 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.]

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);

//output

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.

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 - http://www.palindromelist.net/ 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 http://nifty.stanford.edu/) 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?

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 code.org 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.

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?

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.

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!