Tag Archives: programming

Does Peer Grading Make Students Better Programmers?

The Question

My past few blog posts have been concerned with the usefulness of peer grading.  Steve Joordens showed that peer grading was pedagogically useful for first-year psych students…but what about computer science students?  Would they learn from it?  Would they become better programmers?

We don’t know.

Maybe it’s time to find out.

The Experiment

It’s pretty simple, actually.

I have two groups of students.  Let’s call them groups A and B.

For each student in A, have them complete a simple programming assignment (call it P1).  Once they’re finished, have them complete a second simple programming assignment (call it P2).

For each student in B, have them complete P1.  Once that’s done, have them view 5 or 6 different mocked up submissions, also for P1.  For each submission, have the students fill out a rubric and assign a grade. Once finished, the students then complete P2.

Then, I get some fellow graduate students to mark my mocked up submissions, the group A P1/P2 submissions, and the group B P1/P2 submissions.

If grading made the students better programmers, we should see an increase in the number of marks given to the students in group B for P2.

Bonuses, and Other Concerns

This experiment is nice and simple. And, besides showing if peer grading makes students better programmers, it gives us a couple of bonuses:

  • It tells us if graduate students tend to agree on what marks to give to submissions.  If they don’t agree, and the marks wildly differ…we might have a problem
  • It tells us if some number of students can, on average, approximate the grade a TA would give on a submission
  • It can tell us the average inspection rate for both students and TAs

I’ll have to do randomization here and there to eliminate ordering effects – for example, randomizing the criteria on the rubric, randomizing which assignments go first and second, randomizing the order in which the mock-up submissions are shown, etc.

One thing to consider though:  what effect does simply seeing the rubric have on students?

I’ve been in courses where I’ve not been allowed to see the marking rubric for some assignment.  It’s frustrating.  Seeing the rubric helps me focus on the areas that I’ll be marked on.

So what if just seeing the rubric makes the students “better programmers”?  One way to counteract this would be to have the rubric for the second assignment be quite a bit different than the one for the first assignment.


Oh yeah.  Stats.  Not my strongest subject.  I’m going to have to brush up on this (and probably enlist some help within the department) if I’m going to do this properly.  I’m probably not going to get as many participants as I think I will…so I have to accommodate small N.  Hrm.

Anyhow, this is where my summer experiment seems to heading.  What do you think?  I’m all ears.

The Shoulders of Tall, Smart People

Recently, I came to the realization that I’ve been writing computer programs in one form or another since I was about 6 or 7 years old.

Along the way, I’ve had plenty of people to influence the way I think about code, and how I write it.  Sure, there have been plenty of textbooks along the way too, but I want to give some thanks to the people who have directly affected my abilities to do what I do.

And what better way of doing that then by listing them?

A Chronological List of People Who Have Influenced My Coding

  1. My parents, for bringing home our first family computer.  It was an 8088XT IBM Clone – no hard drive, 640K of RAM, dual 5 1/4 floppies…it was awesome.  This is the computer I started coding on – but I couldn’t have started without…
  2. My Uncle Mark and my Aunt Soo.  Both have degrees in Computer Science from the University of Waterloo (that’s where they met).  My recollection is pretty vague, but I’m pretty sure that a lot of the programming texts in my house (a big blue QuickBasic manual comes to mind) surely didn’t come from my parents – must have been those two.  With the book in one hand, and the 8088 in the other, I cranked out stupid little programs, little text adventure games, quizzes, etc.
  3. The online QB community from the late 1990’s to the early 2000’s.  When my family got online, I soon found myself hanging out at NeoZones, in the #quickbasic IRC channel on EFNet… actually, a lot of crazy stuff was being done with QuickBasic back then – I remember when DirectQB came out, and somebody was able to code a raytracer…in BASIC.  It was awesome.  I’d say these were my foundation years, when I learned all of my programming fundamentals.
  4. My friends Nick Braun, Joel Beck, and Doug McQuiggan – these three guys and I used to come up with crazy ideas for games, and I’d try to program them.  I’d come home from school, and pound out code for a computer game for a few hours in the basement.  More often then not, these projects would simply be abandoned, but still, a lot was learned here.
    Joel, Doug, our friend Julian and myself were also members of a band in highschool.  It was my job to build and maintain the band website, and this is when I learned to write HTML, basic Perl, and simple JavaScript.
  5. After highschool, I went into Electrical and Computer Engineering at the University of Toronto.  I didn’t do too well at the Electrical bits, but I could handle myself at the Computer bits.  I learned OOP, Java, and basic design patterns from Prof. James McLean.
  6. I also learned a great deal from Prof. McLean’s course text – Introduction to Computer Science Using Java by Prof. John Carter.  I know I said I wasn’t going to mention textbooks, but I also got taught Discrete Mathematics from Prof. Carter, so I thought I’d toss him in too.
  7. My second (and last) semester in ECE had me taking Programming Fundamentals with Prof. Tarak Abdelrahman.  I learned basic C++ from Prof. Abdelrahman, and how to deal with large systems of code.
  8. After my move to the Arts & Science Faculty, I took my first Computer Science course with Dr. Jim Clarke. I learned about Unit Testing, and more design patterns.  I also eventually learned some basic Python from him, but I think it was in another course.
  9. I took CSC258 with Prof. Eric Hehner, and learned about the structure of computer processors.  Physically, this was a low-level as I’d ever gotten to computers.  I was familiar with writing Assembly from my QB days, but Prof. Hehner’s Opcode exercises were really quite challenging – in a pleasant way.  Also, check out his concept of Quote Notation
  10. After that year, I spent the first of three summers working for the District School Board of Niagara.  Ken Pidgen was my manager, Mila Shostak was my supervisor.  Ken gave me incredible freedom to work, and soon I was developing web applications, as opposed to just fixing up department websites (as I originally thought I would be doing).  Mila gave me guidance, and showed me how to use CSS to style a website.  She also got me started using PHP and MySQL to create basic web applications.
  11. While working at the Board, I had the pleasure of sitting across from Jong Lee.  Jong and I would bounce ideas off of one another when we’d get stuck on a programming problem.  He was very experienced, and I learned lots of practical programming techniques from him.
  12. Michael Langlois and Ken Redekop acted as my clients at the Board, and always gave me interesting jobs and challenges to perform.Everyone at the Board was always very positive with me, and I’ll always be grateful that they took a newbie undergrad under their wing!  I was given a ridiculous amount of freedom at the Board, and was allowed to experiment with various technologies to get the job done.  Through my three summers there, I learned bits about Rails, CakePHP, MVC, network security, how to deploy an application remotely, how to run a local server, how to develop locally and post to remote, ORM, Flash, web security…so many things.  The list is huge.
  13. Karen Reid and Greg Wilson have been the latest influences on me.  The MarkUs Project was the first project I’ve ever worked on with a team.  It was my first time seriously using version control, my first time using a project management portal (Dr. Project), my first time learning Ruby, and my first time working on an open source project.  I’ve also learned plenty about time management, people, the business of software, and how to get things done.  Again, I’ve been given lots of freedom to learn, experiment, and hone my craft.

Anyhow, these are the people who come to mind.  I might add to this list if I remember anyone else.

But in the mean time, for the people listed above:  thank you.

Making my First Firefox Extension…in 90 Minutes

It’s a race.

I’m going to attempt to create a simple Firefox extension that will display the DOM ID of an element that my mouse cursor is hovering over in the status bar.

There are probably a ton of Firefox extensions that will do that already, but I want to give it a shot as a project.

It’s 3:30PM right now, and I want to try to get this done by 5:00PM.  I’m going to be using Ubuntu 8.04, gEdit, and Google to get me started.

And I’m going to record my progress here in this blog post.

Note: After I’m done, I’m going to edit my sporadic notes so that they make more sense.  So if you’re wondering just how I managed to stay so cool, calm, and collected in my prose under such time pressure, and why the publish date on this article is after 5PM, now you know.


Gonna start with Google:  “building a firefox extension”

Ok, found an article about how to create a Firefox extension.

Apparently, the first thing I want to do is try setting up a development profile in Firefox.


Finished setting up my dev profile by opening up FF with this command:

firefox -no-remote -P

Then created a profile called “Development”.  After that, I typed “about:config” in the URL bar, and changed some settings as instructed on this site.


According to that last article, I can create a skeleton Extension project using this site.  Done – calling the project DOM ID Displayer


Installed this Extension – apparently, it’ll be some help.  Will let me reload Firefox’s chrome  shtuff without restarting the browser each time.  Useful.


Found this article on making a status bar extension in XUL.  Easy as pie.


Ok, I’ve coded something in XUL that should display a new panel in the status bar.

<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet href="chrome://domiddisplayer/skin/overlay.css" type="text/css"?>
<!DOCTYPE overlay SYSTEM "chrome://domiddisplayer/locale/domiddisplayer.dtd">

<overlay id="domiddisplayer-overlay" xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
<script src="overlay.js"/>

<!-- Firefox -->
<statusbar id="status-bar">
  <statusbarpanel id="domiddisplayer" label="Hello, World!" tooltiptext="Dom ID Displayer" />

I put that in the “overlay.js” file in my ~/Experiments/Extensions/domidinspector/content folder that was created using that Wizard from 3:49.

Now, to get this thing to run in my Development profile, I create a symbolic link to it in the Development profile’s extensions directory

ln -s ~/Projects/Experiments/Extensions/domidinspector ~/.mozilla/firefox/nzuzbdpz.Development/extensions/domiddisplayer@mike.conley

Open Firefox with Development profile:

firefox -P Development &


Looks like I can access and relabel the XULElement that I’ve ID’d as “domiddisplayer” using this:

domiddisplayer.updateDisplay = function(event) {
var dom_element_id = event.relatedTarget.id;
document.getElementById('domiddisplayer').setAttribute('label', dom_element_id);

Cool – I can now change my text in the Firefox status window.  Now I just need to capture any time a mouse moves over a DOM element….yikes, that might be tricky.


Been tinkering with this as a way of putting a mouseover event listener on everything in the window:

window.addEventListener("mouseover", function(e) {
}, false);


Seems to only be capturing mouseover/mouseout events on Chrome elements – so I can get the ID’s of the statusbar, etc.  These are XUL Elements, not the DOM elements of a web page…

So I’m close.


This page is super helpful…

Apparently, I need to wait for the content of the page to load before I can attach observers to all of its sub-elements.  Makes total sense.

So, in my domiddisplayer.onLoad function, I write this:

var appcontent = document.getElementById("appcontent");
  appcontent.addEventListener("DOMContentLoaded", domiddisplayer.onPageLoad, true);

And now, I create a function called onPageLoad, which looks like this:

domiddisplayer.onPageLoad = function(aEvent) {
//Runs when the page is loaded
  function(e) {
  }, false);


Done.  I’m over time, but I’ve finished a (relatively) working extension.

Here, it’s a mess, but you can download the whole thing right here if you want to tinker with what I did.

Download domiddisplayer.zip