thoughts on a python programming competition

NCSS Challenge: The National Computer Science School python programming competition run by the School of Information Technologies, at the University of Sydney

I'm on long service leave, so I had time to participate in this competition, since they encourage teacher participation. NB. I would not have had time for it - no way - if I had been teaching.

I was very rusty on my python programming. Having the intensity of a competition with strict deadlines (complete 5 challenges a week for 5 weeks) provided some clear structure and pressure to get on with it

My general view about programming is that it is hard to learn. I'm also quite keen to improve my skill because for me programming has a deep sense of epistemological importance wrt to future of the human race. Two links and one quote about this. Why program? What is programming?

(Abelson and Sussman)....writing a computer program is really about the intellectually difficult task of how to control a complex system. The programming language provides us with a means to express and explore ideas about this which would otherwise be too complex to manage.

Each participant is given a profile page where, inter alia, they can enter their code into a window. A server runs some tests on the code which then provides feedback and whether your code was successful or not. You have 5 tries before you lose any points, which is a necessary feature for a machine check. Although far from perfect this mechanism does mean that the organisers do not become snowed under with marking. The negative is that it also limits the creativity or individuality of the competition, unlike some Game Maker competitions I have recently been involved with.

Forums are also provided. One of the forums allows participants to put in a query for code they think should work but which doesn't. I used this a few times. Then a real person evaluates your code and gives you some feedback.

So, there is a combination of machine checking and human checking which minimises work load for the organisers but provides necessary human to human feedback for those who are puzzled with a hard problem. The testing process meant that you had to finish off your program completely to pass all the tests. If you didn't then you received zero points

In the main this feedback mechanism worked well for me. ie. normally the feedback (either machine or human) made sense and I could then proceed to improve my code. Sometimes I thought the tests were either mean (not explained in the challenge) or trivial (eg. "!" missing in a print statement) but the 5 point buffer made up for that.

It was a competition. There was scoring with points, a leader board was published etc. Overall, I found this provided focus and was motivating. However, when I couldn't solve the spreadsheet problem fully after 4 days it made me dispirited for a while. So it could be hard for those struggling with the basics more than me.

The challenges varied in difficulty from easy to hard (my opinion). Examples of hard problems included a spreadsheet simulation (I learnt about eval in doing this one, but still didn't manage to meet all the criteria in time) and programming a MUD.

The challenges focused pretty much on the maths and logic domain. My logical thinking mechanisms have been give a good workout! The sort of things covered required me to improve my skills in the use of strings, lists, dictionaries, conditionals and importing and reading files. For example, one of the problems involved reading in an English to German dictionary (provided) and programming some translations of nouns from English to German and back again. Other problems involved sequences, working out what the sequence was and then writing a program to provide the correct output for an input sequence number.

So, my criticism here is that this is reinforcing an already stereotyped pool of recruits into programming, those who are already good at maths and logic. I think more than this will be required to reverse the trend of declining IT enrollments to courses. Read Mark Guzdial's post, The Wonderful Opportunities of the Declining Enrollment Crisis

Briefly, here are some of the things I learnt or beliefs which were reinforced from the programming part of the competition:

• computer programming is not easy (I've already said that)
• you need to put in the hours
• it's necessary to have some large slabs of uninterrupted time, the very thing that nearly all teachers do not have
• sometimes logic errors totally confound me, initially, I just cannot see how the error message I am receiving, either from python traceback, or, from the competition automatic tests, could possibly be correct
• but then it's either terribly frustrating or wonderfully elating when some time later your next effort either succeeds or fails
• surely I'm not the only programmer who experiences despair and / or elation
• more than once I did not read the question thoroughly enough and this led to errors which could have been avoided - pretty funny since I'm a teacher who sometimes tell students to read the question carefully and then become frustrated sometimes when they don't seem to
• overall the testing process pushed me in the direction of becoming more rigorous and proactive, to think before submitting code - to question some of my "she'll be right, mate" attitudes
  
• you need a good reference manual, pp. 49-50 of Python in a Nutshell (list and dictionary methods) has become well worn.

Many thanks to the IT crew at University of Sydney for organising this.