Dreidel Game–A Chanukah Programming Project

If you’re anything like me, you like to assign projects that have some relationship to what is going on in the world. Holidays are one such thing. December brings the Jewish holiday of Chanukah – usually right before Christmas. The Dreidel game is a game traditionally played during the Chanukah celebration. It is played with a top that has four flat sides. Each side has a letter of the Hebrew alphabet.

ש Shin ה Hey ג Gimmel נ Nun

The game has multiple players each of whom is given the same number of tokens. Players all place one token in to a “pot” and spin the dreidel to see who goes first. The player who spins the highest value starts. Note: nun is highest, then gimmel, hey, and shin. If there is a tie, the players who tied spin again.

Each player takes turn spinning the dreidel and taking an action depending on what letter they spin.

* Shin: put one more token in the pot
* Nun: do nothing
* Gimmel: take all tokens from the pot
* Hay: take half of all tokens lying in the pot.In case of an odd number of tokens, round up.

The game ends when one player has all the tokens or after some set period of time or mutual agreement.

There are lots of ways to program this of course. Normally, at this point in the semester I have been teaching students how to create simple classes. So when I wrote my solution I created a dreidel class. There are some reasons that this makes for a nice class to create. There is the usual protected data – the face value of the dreidel. And there is the obvious spin and get value methods. I also over loaded the ToString and CompareTo methods.

The ToString method allows for displaying the name of the face value of the dreidel. CompareTo is particularly useful for selecting the high spin at the beginning of the game.

I also added some public const values for the face values so that I could use them in calling programs without the programmer needing to know what the actual values are.

if (player.Value== Dreidel.Shin)

Here we have a fairly simple game to program with a class that lets the programmer do some interesting overloads and activities without too much complexity.

Inspired by a project idea posted on the AP CS Teachers Facebook group group (https://www.facebook.com/groups/APComputerSciencePrinciples/permalink/1873272652824371/)  Thanks to Lee Whiteley for sharing with the community..

New Resources for Teaching and Learning about Artificial Intelligence

Earlier this week I was a guest speaker in a computer science class (via Zoom of course). It was fun to be back into a class and interacting with students. The students were asked to prepare questions for me and many of the questions were about artificial intelligence. That’s not surprising as AI has really jumped into the public in ways it hasn’t before. That’s why it is timely that code.org has created a new resource for teaching and learning about AI.

The main resource page for this is at https://code.org/ai There you will find a bunch of short videos of 3 to 5 minutes that cover various aspects of AI. Several of the videos explicitly focus on getting people to think about the ethics involved. Satya Nadal, Microsoft CEO, in his introduction makes one of my favorite points right off the bat. It is not enough to think about what computers can do but we also need to think about what computers SHOULD do. Ethics are woven into all the videos and not just the once focusing on ethics.

The videos are typical code.org videos. That means high production values and a diversity of impressive speakers. Presenters represent a variety of ages, races, and colors. They are all impressive and are practitioners in the fields of AI. There are academics and there are people from industry. They really highlight a broad cross section of people involved in AI today.

Besides the code.org videos there are links to videos from other organizations, lesson plans, and activities powered by artificial intelligence and machine learning. And more. It’s a great place to start building the set of curriculum that will work for your course and the age group you teach.

Why Do I care About This Program I am Coding?

Why do we program? Well, for some of us it is because we get paid to write code. For some it is part of our learning experiences. For a few it is the fun of it. There are a lot of motivations and they are different for different people. A couple of posts have been thinking about this lately.

Mike Zamansky has bee posting about the Advent of Code event. (Mike’s initial post here Advent of Code 2020)  Today I replied to his post about the first puzzle with the following.

I struggle with these problems a bit. Not because of the technical issues but because of motivation. Or perhaps relevance.  Why would I need to do this? What interesting or important problem does it solve? I guess the issue for me is that solving a problem for the sake of solving a problem, proving that I can did it basically, is not motivating to me. Maybe I have been programming too long to feel like I need to prove anything to myself. OR anyone else for that matter. I get that for some the challenge is enough motivation and that they get satisfaction from the effort. The journey being more important than the destination I guess. And that is fine and if people enjoy doing it that is wonderful. I'm happy for them. It just doesn't motivate me.

As I thought about it, this also related to a post by Mark Guzdial recently. Purpose-first programming: A programming learning approach for learners who care most about what code achieves: Katie Cunningham’s Defense I hope to be able to hear Katie’s defense tomorrow. And look up her papers.

When we as educators assign projects or do demos, what is the purpose of of the code? And does anyone care about it? Students work harder and longer, it seems to me, on projects that they care about. Not just for the grade though that motivates some. Do they want to see the program work for themselves? I always found that the hardest working most motivating projects were the ones students selected or decided upon on their own. Projects that solve problems that are meaningful for them are much more effective than projects that are more about “just do this to learn how this concept works.

I’ve been playing with code myself lately. Each project has taught me something but I was motivated more to solve a problems that was interesting to me than to learn the new concept/algorithm/language feature or what ever I learned. This is what we as educators need to bring to our students in my opinion. They have to care about the problem and not just the grade.

Does It Matter How Fast the Code Is?

I’ve been having a lot of fun playing with code lately. One of the things I have been experimenting with is cryptography (See Tiny Book of Simple Cryptography) For one project I wanted to create a string of ones and zeros to represent the binary value of letters. I quickly came up with three ways of doing this. I know that are probably many more ways than that. But for now I have some that work and one of them I really like.

Which one is best? Well, that depends. Which one is the fastest? That depends as well. I think I know which one is fastest. It uses the bitwise & operation which generally is pretty quick. One used the Math.Pow function which I suspect slows things down quite a bit. The third uses nothing fancy at all and could easily be coded by someone with only a little programming knowledge. I suspect it is the middle in speed/ Does the speed matter though?

In this application , probably not. The bottleneck in performance is going to be in the I/O not the calculations. The performance of this function is lost in the noise.

What probably matters more, if one is looking to define “best”, is which algorithm is easier to understand..

I learned this lesson one day back when I was writing code for a living. We were doing a formal code review of my code and I had written what I thought was a very clever piece of code that was pretty efficient. The review made me rewrite it using code that was no where near as clever or interesting. It was, however, a lot easier for someone new to the code to understand. And that was more important.

Now there are applications where performance is critical. I remember working with a company building a system  to collect weather data. They collected a huge amount of data is a very short period of time. They were actually comparing the instruction execution times of various machine language instructions to pick the computer they were going to buy. That’s pretty exceptional though.

To complicate matters even more, today’s optimizing compilers are very smart. It is rare that a person coded Assembly language program can outperform code generated by an optimizing compiler. I was involved in actual benchmarks of this in the 1980s and things are improved since then. Take these two pieces of code:

if (foo % 2 == 1)

label1.Text = "Odd";

if ((foo & 1)==1)

label2.Text = "Odd";

Which one is faster? You may think the second one is faster. You might be right. On the other hand, a really smart compiler by generate the same low-level code from both of them. Unless you were on the compiler writing team you probably don’t know. Even if you have the source code for the compiler do you really want to spend the time to see how it is optimized?  You couple probably also look at the generated code but is that worth it either? Not generally.

The first example is clearer. A number of my friends who write code for a living tell me that is what they would use. Because it is clearer and understandable by more people it is not worth worrying about an optimization that may already be taken care of for them by the compiler.

Once upon a time it mattered a great deal if one iterated though a two dimensional array by column first or by row first.  One had to know which was faster and do it right. Today, compilers take most of the worry about this away from us. We can do it in the way that seems more logical for us and for the application.

One of my friends who has worked on compiler development teams tells me that conversations about this sort of optimization are frequent there. People working on compilers have the time and the experience to make compilers smart. I’m pretty sure more of them (the people and the compilers) are smarter about code optimization than I am.

That doesn’t mean we can ignore performance. I’ve seen some beginner code that is horrible in performance. But still there are trade offs. I once wrote a very slow program that I ran once a month. I thought about a way to optimize it that would cut a minute or two off of the run time. It would have taken me an hour to code and that was a lot more time than it would have saved me. Turns out a faster computer a few months later ran the inefficient code a lot faster anyway.

Honestly, though discussion optimization and performance can be fun for a certain class of geek. Geeks like me.

The Making of a Computer Science Teacher

There is quite the conversation going on in the private Computer Science Educators group on Facebook about teacher preparation for CS educators. This is a very interesting group for CS educators BTW. Join if you are on Facebook. I link to some specific articles at the end.

It’s a lot more complicated question than it might appear. There is the argument about what CS educators need to know to teach CS effectively. Is something better than nothing or is not enough going to mean poorly prepared students? Given all the complaints I have heard from university people about high school students being taught CS wrong (what ever that means) I tend to believe that CS educators should have a lot more depth of knowledge than the courses they are teaching. Definitely more depth than their students will get from the course. We expect this from teachers of other subjects (for the most part – see highly qualified teacher).

As to preparation, and its close cousin – certification – we are dealing wtih three main types of people who need preparation to teach CS.

• Teachers of other subjects
• CS experienced people moving into teaching
• Career beginners who are not previously teachers or CS people

They all need something different. I have heard people say that a good teacher can teach any subject after learning some content knowledge. I would argue that teaching CS is different from teaching most other subjects. A teacher needs to know how to teach computer science. We've been fortunate over the last decade or two that some serious research in how to teach CS has been done. CS teachers need to know what has been learned about HOW to teach.

Teachers of other subjects also need some solid content knowledge. Topping out at the content involved in AP CS Principles and AP CS A (the top high school cs courses) is not enough. Well, not for high school CS teachers. Students are going to ask deeper questions than what is required and you can only get by with “well, let’s look that up” so often before people start to wonder if you know what you are doing.

How much do you need? And this goes for people new to teaching as well as just new to teaching CS. That’s a struggle. I don’t think you can get it in two one semester courses let alone a couple of weeks worth of summer workshops. Two semesters of programming is probably the minimum for that aspect. In the first one a person learns a programming language and a start of how to solve problems. It takes a second course to really become a programmer. Of course there is a lot more to computer science than programming. Vocabulary, networking, algorithms, security, CS ethics, and well, if your have taught AP CS Principles you get the rest. So three or four semesters of real CS.

Everyone who teaches CS including those new to teaching and those career changes needs a course or two (or three) if pedagogy. A focus on teaching CS for sure but also some work on test development and evaluation and classroom management. Do they teach classroom management in regular education programs? CS has some interesting complications involving students playing on the internet and messing with lab computers.

I also think that CS teachers, especially now when there are seldom multiple CS teachers in a building, need to learn about external resources. Social media, CSTA, summer workshops and conferences, StackOverflow, and generally how to build a network to support your growth as a CS teacher.

To prepare to be a great CS teacher is going to take a lot of work. Yes, people do figure it out on their own I know people, I am one, who came to industry without training in teaching and did a pretty good job. Enthusiasm and great students will get you pretty far. That’s not the ideal I look back and wonder how much better my students would have been if I had known what I know about teaching CS back then. I don’t think I messed anyone up too much but could I have taken them further? I like to think so.

If CS is going to take its place with other core subjects we have to learn to teach it well. We have to have more than just enthusiasm for the subject.. We have to set high standards for teachers as well as students.

Facebook Conversations

• https://www.facebook.com/groups/cptrscied/permalink/886841201720689/
• https://www.facebook.com/groups/cptrscied/permalink/886035605134582/

Mike Zamansky’s post of the subject https://cestlaz.github.io/post/teachers-can-learn-cs/

Tiny Book of Simple Cryptography

I've been playing with simple cryptography. Mostly stuff that was solid before computers. Just for fun mostly but some of it may make for interesting projects for students. I've written a little bit about the things I have been playing with.

This is not a big book and it is intended more to spark interest and not to be a real reference book. There are footnotes linking to Wikipedia articles that would be a good next step for learning more.

I have a couple of substitution ciphers and a couple of  transposition ciphers. Added some Steganography. 

http://www.acthompson.net/TinyCrypto.pdf

Comments and gentle criticism welcome. I have coded solutions in C# that are ok. Some of them even have comments.

Updated 5 March 2021 to include a brief chapter on the PigPen Cipher. Also some minor edits in other sections.

TileCode–Creating games on and for handheld devices

People are Microsoft always seem to be working on interesting and unexpected (to me anyway) things.  My most recent discovery is TileCode. From the website:

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Microsoft TileCode is an app for designing, coding, and playing video games directly on low-cost MakeCode Arcade gaming handhelds, as well as in the web browser. With TileCode, we are using the medium of video games to explore the combination of

• Natural language for informally specifying games goals, rules, and mechanics;
• Physical computational models that foreground concepts such as data parallelism, pattern matching, and conflict resolution;
• Testing and debugging of programs to establish confidence in their behavior and to refine specifications;
• Machine learning to help bridge the gap between natural language and programs, as well as to generate non-player character behavior in games.

Our ultimate goal is to provide a sandbox in which students can express and refine their game ideas, while learning about computation, programming, and machine learning, supported by software engineering practices.

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It's a pretty interesting idea. I wonder how it might work in classrooms. There is a webinar about their research later in November that I hope to sit in on.

TileCode builds on a lot of previous work and not just from Microsoft. It builds on Kodu and MakeCode but they reference a lot of other block based tools in their paper - TileCode: Creation of Video Games on Gaming Handhelds

I'm really fascinated by the work I am seeing in domain specific tools lately. While games are a popular topic I'm been following Mark Guzdial's work with domain specific languages for Social Studies with interest. I tend to think that rather than see artificial intelligence take over the job of programming that we’ll see more and more domain specific languages (should we call them tools?) that people will use.  I’m not convinced that AI and machine learning will know when rules are really guidelines.

What If We Asked Students To Write Textbooks?

A professor friend on Facebook posted that a student emailed him to say that they textbook the were using was “crap.” I suggested in jest that he asked the student to write a better one. That’s pretty tough since how do you write a textbook about something you are learning as you go? (Can be done. Is painful. Don’t ask how I know this.)

The exchange got me thinking though. Supposed we asked students to write a chapter for a mock textbook? Or perhaps asked them to write step by step instructions for completing an exercise assignment. After it was covered in class but perhaps in lieu of a test.

I think it would be interesting to see how students explain concepts. Have they write to explain things to people their own age. How would they explain things? What words would they use? What examples would they give?

They say that to really understand something you have to be able to explain it to others. 

Somehow I don’t think most students would like this exercise though. Of course we already ask students to do things they don’t like – taking tests being one of them.  I do think that it would give us insights into what they do understand and how they understand it. Or misunderstand it as the case maybe.

Anyone want to try it?

Thinking About the Algorithms in Our Lives

My wife and I use these fitness trackers, ours are made by Garmin, to keep track of our activity during the day. Each day the devices give us a goal for how many steps we should take that day.  The goal goes up or down depending on how many steps we did on the previous day. I think. Maybe.

Being the computer guy that I am I keep thinking about how the algorithm actually works. Is it a simple algorithm based on some sort of average or does it have some amount of smarts? Does it take several days activity into account or just the previous days? Like so many things in our lives the algorithm is completely opaque to users.

Google Page Rank, the algorithms that run on the computers controlling our cars, and the software John Deere uses to control the equipment they make. (see article linked below for way this opacity is a problem for some) are all secret. Why?

Well, various companies have various reasons for keeping their algorithms secret. Competitive advantage is the reason for some. For many it is to keep people from “gaming the system.” Google, and other search engines, don’t want people to find ways to get unfairly high placement in searches. I suspect some of that is involved in my Garmin’s secrecy. For others, it is about keeping control of the how the systems them make are run – often for the sake of safety. That’s why many companies don’t want their software “messed with.”

How good or bad this is for the consumer is quite up for debate. There are solid arguments on both side. Arguably, the right thing depends on the situation in many (perhaps most) cases. These are issues we need to think about going forward. People who write software and create algorithms have a responsibility to make the right decisions about secrecy or openness. The decisions have to be about more than just money as well.

Do you discuss these issues with students? I think we need to do so.

Farmers Fight John Deere Over Who Gets to Fix an $800,000 Tractor

Artificial Intelligence, Humor, and Appreciation of Beauty

Last night I started re-reading Heinlein’s The Moon Is A Harsh Mistress.  It’s an old book, written in the mid 1960s, so there are some old ideas about computers and computing in it for sure. There is some hand waving about how AI is done and how the computer, Mike or Mycroft Holmes, becomes self aware. It is fiction after all. The computer is trying to understand humor and a human friend is trying to help. One way he is helping is to get lists of jokes and report back on which jokes are funny, which are funny once, and which ones are always funny. That sounds a bit like machine learning we see today I think.

In any case, even is the computer does understand humor at some level and is able to create jokes that people find funny does that mean it has a real sense of humor? Will it be able to laugh at jokes that are not in its system? I wonder.

This makes me wonder about other things. We know that AI has been able to write music that people enjoy and create art that looks like it was done by master artists. Is creating art or music the same as enjoying art and music? Maybe not. Now human artists “hear” music in their heads before they write it down or play it. Beethoven write music while he was deaf and so could not hear it being played.

I’ve been to a number of wine tastings. I don’t like wine. No matter how many times I taste it I just don’t enjoy the taste. Listening to wine experts talk about wine and tasting it myself I think (could be wrong) I could learn to identify the wines that wine lovers like. I don’t see me enjoying the process very much though. Understanding is not the same as enjoying. Is it the same for computers and AI? I think so.Recognizing beauty or humor or music is not the same as enjoying it.

The difference between humans and AI is that humans enjoy their creations. And they enjoy the creations of others. If we think about creating beauty as enough to  being human-like  I think we have a narrow view of humans. What do you think?

MicroBlocks For IoT and other Physical Computing

Well, there is a new tool in town for programming micro devices like the Micro:bit and the AdaFruit Circuit Playground Express and many more! It's called MicroBlocks and was created by a rock star team with experience with creation of such tools as Scratch and Snap!. It’s pretty exciting for a number of reasons. One of them is the wide variety of devices it works with. Another is the Natural Languages it supports.

Live Coding is another interesting feature.

MicroBlocks is a live environment. Click on a block and it runs immediately, right on the board. Try out commands. See and graph sensor values in real time. No more waiting for code to compile and download.

And Multi Tasking.

Want to display an animation while controlling a motor? No problem! MicroBlocks lets you write separate scripts for each task and run them at the same time. Your code is simpler to write and easier to understand

I played with it a bit and it looks pretty intuitive especially for those with previous block programming experience. I made the mistake of trying it without having a device to use with it handy. I have several at home and so I’ll be trying them next week. But I wanted to get the word out so that if people want to try it over the weekend (yeah, I know you don’t have as much free time as you want) or have some students try it out you could.

Sometime next week I want to do a side by side comparison with MakeCode which supports several of the same devices. Some obvious differences are that MicroBlocks supports running the exact same app on different types of devices and that MakeCode has emulators. Since most people only use one type at a time and have physical devices the impact of those differences will be different in different environments.

We are living in exciting times!

What I miss and don’t miss about teaching

Fall has come and while students are back in school I am not. I’ve been reflecting a bit about that. I don’t miss getting up at 6 AM and driving for close to an hour to get to school. I don’t miss running my life by a bell schedule. I don’t miss grading, report cards, and other administrivia. I don’t miss classroom management issues.

On the other hand, I do miss interacting with students. I especially miss the interactions that take place outside of class. I miss the look, and sound, of students when they get a concept or when their program works – finally. I miss debugging student problems with programs or their project. Students are very good at finding ways to mess up a Visual Studio project. That’s the one big downside to using a professional tool. But I had fun putting things back together.

There are all sort of debugging issues that come up in the code. There is syntax issues (semi colon hide and seek anyone?) and logic problems. Both are fun little puzzles to solve. And I am sure there are still many that students have not discovered.

But the big miss is the students. I still think I retired at the right time for me.

I hope your school year is going well. I am following all sort of teacher/school things on social media and I know its not easy. Stay safe. And if you have a student program you can’t debug let me know.

Why Computer Science Teachers Should Read Books

Since I retired I have been reading more computer science related books. You may have read my book reviews on Humble Pi, Weapons of Math Destruction, or Computer Science in K-12. More and more I realize that I missed out on a lot of good ideas and information. Each of those books has given me ideas that I wish I had thought of a long time ago.

Currently, I am reading Nine Algorithms That Changed the Future: The Ingenious Ideas That Drive Today's Computers. I haven’t gotten very far yet but the book has covered indexing of web pages, PageRank, and public key encryption so far. I’ve started the chapter on error detection. Pattern recognition, data compression, data bases, and more are yet to come. I’m really looking forward to data compression. Teaching AP CS Principles has built up an interest that I didn’t have before.

The indexing chapter is one I had read long ago. Many years ago I experimented with indexing. I wrote some code that indexed the Bible for me. The program was more general purpose than that but the Bible seemed like a good challenge. The program used a list of words and a text file of a book as input. It output a markup language file that worked with a product called VAX Document. VAX Document read the markup language, called SDML, and formatted a document including an index. I wish I still had the code so I could adapt it for some other backend processors. Sigh.

In any case, the idea of creating and assigning indexing projects has some appeal for me. I can see this being interesting for students especially in the context of understanding search engines and more involved search queries.

Other chapters include a lot of information that would be helpful in understanding and explaining various important concepts. And maybe inspire still more programming projects!  So I do recommend this book to AP CS Principles teachers.

PS: More of my book reviews at http://blog.acthompson.net/search/label/book%20reviews

How Are You Doing?

We’ve now finished the first week after Labor Day and at least in North America almost everyone is back to school. That may not mean physically back in a bricks and mortar school building though. My grandson is starting kindergarten online this week. I didn’t see that coming a year ago. Teachers, students, and parents are adopting to all sorts of new ways of teaching and learning. 

I confess to being happy I am retired but I am also sympathetic so those still teaching. I do worry about you all. I hope you are finding ways to take care of yourself.

My son is an elementary school principal and his summer was as busy, if not more so, than during the middle of the school year. Administrators have been having a tough time so have some sympathy for them.

Somehow many people seem to think this is all easier for computer science teachers. This is not the case of course. Yes, we may be more comfortable with computers than some teachers but the tools for teaching online are new to us as well. And helping students with computer problems is as hands on as helping students in art, or math, or English. Maybe more so at times.

I think we’ll see some tools appear and older tools will see new features develop Social media is full of teachers talking about online IDEs for example. I’m still not a fan but that’s me. I still like the idea of using virtual machines on a powerful server for teaching computer science..  No doubt a lot of people will be trying new things. If nothing else, we’re going to learn a lot this year about new tools for teaching CS.

And that brings me to a final point, have you thought about sharing what you are learning with other computer science educators? The call for proposals for CSTA 2021 is out. Even if you are learning a lot of what doesn’t work you are learning some things that do work. We’re all better off if we all share what we are learning. Please consider a proposal for the conference. If you have questions about what is involved let me know. I love presenting at CSTA conferences. It’s the best audience you could have. Seriously!

The End of School Computer Labs?

There has been a lot of talk in recent years about doing away with computer labs in schools. BYOD and one to one computers have been talked about and have been growing movements for a while. I wonder if the current situation will be the final tipping point.

My old school removed the computers from the computer labs. The work involved in constantly sterilizing and cleaning them was becoming too much. So students bring their own devices and now connect to virtual machines via the network. They have access to all the school’s licensed software no matter what device. This worked great when we moved to remote learning in the spring.

Besides the cleaning/sterilizing issue this means a lot of new flexibility. Of course it makes it easier if school has to close and students have to learn from home. But in school it opens more rooms for teaching. And if you have small rooms classes can even be split across rooms with teachers in one room, or even at home, teaching to several rooms with safety distancing.

I computer room can have a more flexible layout, perhaps with easily movable tables for group work, focusing on a lecture, or just plain spreading out.

Will computer labs now totally disappear? We’ll see. A lot depends on a willingness and ability to provide computers for every student. That’s easier in wealthy areas than poor ones. But it just may be the way things have to be.

Book Review: Humble Pi

Recently, I asked my Facebook friends for recommendations for non-fiction books that would not get me depressed. Several people recommended Humble Pi: When Math Goes Wrong in the Real World so I bought a copy. I’m glad I did.

The book presents some interesting case studies in math done wrong. From people confusing units of measure (pounds and kilograms for example)  to engineers changing one variable in an equation and assuming the answer doesn’t change and many more. As you might expect there are a lot of examples where computers play a role.

There are examples of problems caused by variable type mismatches, binary overflows, and people just misinterpreting the results. You’ll get any number of examples you can use with students. A valuable book to teachers of computer science, physics, and mathematics for sure.

The book is written in an easy to read and often humorous fashion. It’s an enjoyable read even if you are “not a math person.” I bought the Kindle edition but I am wishing I hard bought a hardcopy edition to keep on my bookshelf. I’ll be back looking at this one.

Are You Ready to Help with CSTA 2021

The call for participation in CSTA 2021 is now out. You can learn about the submission process and look at some possible topic areas on the conference information page here. There are several ways to help out with the conference (see below). You can present or you can become a reviewer. Both are very important roles.

I encourage CS teachers to consider submitting a proposal to present. I have been honored to present at the CSTA conference a number of times over the years and have found it a very rewarding experience. The audience is kind and anxious to learn. This summer, the conference being online, added a new and extra facet which I found surprisingly energizing. I am hoping, as I think most of us are, that next summer we will be meeting in person. Either way, presenting at CSTA is a great way to be part of the community and to help expand knowledge

Chances are that you tried something new this past spring. Or will be trying something new this fall semester. That means you probably have something worthwhile to share. Don’t be shy!

Reviewers are also critical to having a good conference. Reviewers read and evaluate proposals and are essential in the process of picking the best presentations at the conference. Please think about helping out in this way.

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• Apply to present: We're accepting submissions for a one-hour session, three-hour workshop, 20-minute mini-session, 45-minute Birds of a Feather discussion, or a poster session. Visit our website for more information on the process and to submit your application. All submissions are due by Nov. 8.
• Become a reviewer: We invite you to consider reviewing submissions for CSTA 2020! If you've attended or presented at a prior CSTA conference, have a connection to K–12 computer science, and are available between Nov. 23, and Dec. 17, consider volunteering your time!

Learning Python Part 2: Distracted by a Turtle

I cracked a book and found out that Python supports turtle graphics. I love drawing pictures with graphics. I have since I was in university. So today I played around with the Python turtle a bit.

Mostly I played with a few of the usual turtle methods and wrapping drawing code inside loops. I had some fun but didn’t learn a lot. I’m not sure that was the most productive use of my time.

It did suggest that using graphics with Python is potentially a way to make learning Python more interesting. I have Mark Guzdial’s book on Media Computation around here somewhere. I’m going to dig it out and see if it the libraries for it will work in my environment.  I want to do more than draw lines.

Programming Projects for Learning or Grading

The purpose of school work is to get good grades. Well, at least that seems to be a common view on the part of students. Most teachers will tell you that the motivation for students to cheat is that they are lazy and still want to get good grades.  The recent posts by Mark Guzdial  (linked to at Changing How We Teach Computer Science) have sparked a lot of comments on his blog and on Twitter which had sparked some thoughts on my part.

I have long believed that projects are a great learning exercise for students. I haver become less enamored with them for grading. Cheating seems to show up all to often. Often it is hard to prove cheating because projects are to short, variable names are too likely to be the same logically, and there are limited ways to solve them. I have seen the most creativity and the least cheating (provable or otherwise) on larger projects where students were all doing something completely different.

A common thread in the comments I have been seeing recently is that students cheat not because they are lazy but because they don’t know how to solve the project on their own. This idea resonates strongly with me.  I see a lot of satisfaction on the faces of students who successfully complete projects. They tend to actually enjoy the process when they have success. 

Over the last several years I have increased the number of other means of assessments including multiple choice questions that include reading and understanding code. Comparing quiz results with project results has been interesting. Some students show close correlations between quiz grades and project results. Other students not so much. While I haven’t conducted a rigorous or scientific study by any means, my observations suggest to me that students are copying the projects of others because they haven’t gotten a strong enough grasp of the material. 

I’m pretty convinced that evaluative instruments that require the reading and understanding of code are better tools for understanding what students actually know than looking at projects. That is not to say that looking at projects is useless. To the contrary, students who work hard against the struggle show what they know and don’t know in their code. A project that doesn’t work correctly give a teacher a lot more information about student understanding than a project that works perfectly.

In my ideal world, I would give each student a different project for every concept I want them to demonstrate knowledge of. That is clearly not possible and certainly doesn’t scale to large classes. I’d love to have a way to watch student progress on a project. What do they try and what do they do when things either work or don’t work. I don’t know of a good tool to that right now or even if it is practical. I guess for now teachers will just have to watch students closer.And use other tools for grading and for determining what students actually know.

Learning Python: Part 1

Python has been on my radar for years but I haven’t really had the motivation to learn it myself. It’s time though for several reasons. Reason number one is that I need a learning goal to keep stretching my mind and knowledge. I don’t have a bunch of students finding new puzzles to solve so I have to make my own mistakes.

First step was to pick a development tool. I have played with a bunch. IDLE, PyCharm, Processing, and some I forget. I didn’t like any of them. So I am using Visual Studio. I expect many to tell me that was/is a horrible choice but its the devil I know so there is that. Many of the tools feel like steps backwards to me. I’ve gotten spoiled by the Intellisence in Visual Studio among other features. IDLE felt like what I used to learn BASIC-Plus 40+ years ago. Anyway, I want to spend my time learning a language not an IDE.

OF course there are two parts to learning a new programming language. Part one is the basic syntax. Part two is the idiom of the language. The first part is easy. The second not so much.

I’ve started with easy stuff. Declaration of variables, simple math, declaration of functions, and control flow. IF statements and while loops were pretty straight forward. For loops are different and idiom rears its ugly head here first for me.

For loops in Python seem to be what I think of a ForEach loops in other languages. Very powerful and useful. On the other hand, how do I do the equivalent of:

for (i=0; i <= 100; i+=5)
or
for i =0 to 100 step 5

Or do I need to use a While loop to do this? Go ahead, show off in the comments and help me out.

String manipulation, one of my favorite things to code, is probably next for me.I think that will be ok.  Lists and dictionary come after that. I think I will have to read up on them as they look to be thought of differently than arrays in the languages I am used to using. They also look like fun and powerful to use. So there is that.

Classes after that. Hopefully that moves quickly.

Once I get some basics down I’ll start looking into various libraries and what not. Perhaps go back to try some graphics in Processing. Is there an equivalent to Windows Forms like I use with C# and Visual Basic? Or do I have to go backwards again to do that?

At least I’m having fun. Now to go crack a book.