Tuesday, May 13, 2014

Multiple Choice Exams

Tomorrow I'm giving a final exam for Computer Organization, a common undergraduate course.  The final consists of 40 multiple-choice questions.

I get very nervous when I tell colleagues that I give multiple-choice exams.  No short or long answer sections.  No write-some-code sections.  Just easy multiple-choice questions.  Oh, and often I have a True-False section too.  I'm afraid other educators will see this as going too easy on my students. 

As it turns out, I make it easier.  I also let them bring a "Cheet Sheat" with whatever they want on it to the exam.  (One piece of paper, handwritten, double-sided.) 

Easy enough yet?  Not quite.  I also give them a practice exam ahead of time, with questions that could also appear on the exam.  There is almost always overlap.

Why do I set them up for such over-success?  A quick list of why I think this is okay:

* My questions are quite difficult.  I often try to give them multiple parts to force them to work through a lot of details to figure out which answer is actually correct.  Some of the questions are basic, but others require a lot of consideration.

* I want my students to learn the knowledge-level material.  If I let them bring ultra-condensed notes, I know they'll spend the time writing it all out, which usually commits it to memory.  Often they don't have to reference it at all, which saves them time anyways.

* I want them to comprehend the material.  The time they spend on the practice exam is time well-spent.  I don't give them an answer key, and agree to only talk about one problem at a time.  Then they do their best to understand the material from the beginning.

* I don't want to test their ability to write code.  Almost any time they're doing that in the "real world", they'll have Internet access.  Why force them into an unnatural programming environment?  They have projects all semester that test this reasonably. 

* I don't want to scale exams.  Really.  I don't remember the last time I've done any scaling.  (It hasn't been that long, though; I've only been a professor for 5 years.)  I really like being transparent about grading; scaling makes that more difficult.

* Grading is tough enough.  Especially grading open-ended things, because then it is so easy to be influenced by outside factors (including handwriting and comparisons between students and the order you see each exam).  I really don't like making subjective judgements on grades.

* Questions and answers can be leading.  Learning things on exams is great.  Didn't know how Excess-127 notation works, but figured it out during the exam you've been worried about for days?  Yeah, I bet that will stick with you. :)

* My errors can be easily corrected!  Students are always pointing out errors in the exam during the exam.  I rarely survive an entire exam without every error found and picked apart.  I let them know right away that if they think they see an error, they're probably right and should let me know right away!  This reduces tension over all.

Do these exams replace difficult take-home exams for upper-level courses?  No.  But for intro-level courses, I think they are great at maintaining fairness and enhancing student confidence.

New Hampshire Bound

My one-academic-year position at Colby ends in a few weeks with the college's commencement exercises. 

I'm happy to say that I'm starting an exciting new job in the fall!  I'll be teaching at Plymouth State University in Plymouth, New Hampshire.  I love teaching CS and I continue to be amazed at the relevance of CGT to my teaching.

Yes, I plan to continue blogging.  Yes, I plan to keep playing games.

I've also been working on getting some HTML 5 versions of common combinatorial games working.  I'll make those available once I am settled in with web space at Plymouth State.

Friday, April 18, 2014

CGT Gatherings: May 2014, Oct. 2014, Jan. 2015

I want to make sure I advertise some games meetings that are happening in the next year.  I'm afraid I should have mentioned some sooner!

May 2014 in British Columbia:
Paul Ottaway writes:
I have confirmation that TRU will be happy to host the inaugural "TRUe Games Workshop".  It will be taking place here at Thompson Rivers University in beautiful Kamloops, BC from May 6th - 9th, 2014.
All of the information can be found at www.tru.ca/truegames

Oct. 2014 in Nova Scotia:
Richard Nowakowski writes:
The Math/Stats Dept at Dalhousie will be hosting the AMS NorthEast Section meeting Oct 18 and 19. There will be a special session on Games on Graphs. This is vague enough to cover all versions of Pursuit-Evasion games, combinatorial and positional games provided they are on a graph. I'm the contact person. If you would like to speak please let me know and send me a title and abstract as soon as possible. There is a hard deadline of August 18 to get in your abstracts---no abstract, no talk.

We have a maximum of thirteen 30min slots but we don't have to use all of them

There is no funding available, I'll check with the Graphs and Games group as to whether the group will consider funding some expenses for students.
Jan. 2015 in Portugal:
Carlos Santos gave me the website for the Combinatorial Game Theory Colloquium, an event that will be held every three years!  Exciting!  I'm sure there will be more information about this as the event develops.

Friday, March 21, 2014

Game Description: Yavalath

Last semester, I stumbled on the game Yavalath while browsing reddit.  This game is especially exciting because the rules are very similar to tic-tac-toe type games... except for an excellent twist!

Yavalath is played on a hexagonal board.  Each turn a player paints an empty hexagon their color.  So far, no twist.

If you get four hexagons in a contiguous line, you win.  No more moves are played.  Still no twist.

However, you are not allowed to play in such a way that you get exactly three hexagons in a row.  More than three is fine (and you win) but exactly three is not allowed.  Twist! :)

One problem keeps this from being strictly combinatorial: the board can fill up so that neither player wins.  In this case, you could just announce that the last player is the winner since no more moves exist.  The site gives an example of such a case:

Notice that this position would probably be the result of a sum, as there are an even number of white and black pieces.  Cool!

This is a game Cameron Browne generated with the program Ludi.  I know nothing about automatically generating rulesets, except that it seems to have worked out here.  Yavalath is very fun to play.  I challenged many of my students to quick games before class, and also over lunch.

Tuesday, March 18, 2014

TRUe Games Workshop: May 2014

An annoucement from Paul Ottaway:

This is the second official announcement for the TRUe Games Workshop taking place at Thompson Rivers University in Kamloops, BC from May 6-9, 2014.  Registration is open and even if you've let me know that you'll be attending, we would appreciate a quick email to Marcy at mchristianson@tru.ca if you haven't already done so.  The details regarding the conference are available at www.tru.ca/truegames

I would also like to point out for those making arrangements for accommodations that the Residence and Conference Centre has now released half of our room block but the other half will continue to be held until April 5th.
I wish I could go, but my travel budget is exhausted for this academic year.  This sounds like exactly the sort of awesome workshop that happened at BIRS in 2011.  Paul mentions there will probably be some focus on scoring games, and potentially position games as well.

Friday, March 7, 2014

SIGCSE 2014: Board games in CS2

I'm at SIGCSE for the first time and just saw a cool paper talk about including board games as part of CS2.  The group wound up using Quoridor, a combinatorial game. 

In fact, most (if not all) of the options they considered were combinatorial games.  This makes a lot of sense when you realize they were looking for the following properties:
  • well-established, but obscure (strategies are known and discussed online, but the students probably didn't already know the game)
  • simple rules
  • non-violent
  • race/gender/culture neutral
  • discrete
Students were put into two types of groups:
  • "Engine" groups: Implemented the ruleset
  • "Player" groups: implemented a strategy
The player groups still had to keep track of much of the board state themselves.  Instead of getting the entire game state for each turn, they were just given the most recent change.

It was a great talk and very interesting.  One of the main takeaways from the group is that they would remove the engine group next time and just have all the players working on implementing players.

Here are the paper and the project's website.  There are resources for using their materials, with support for other games aside from Quoridor!

Wednesday, September 25, 2013

Which Abstract Games are Fun?

I recently read a great post from Nick Bentley, a connoisseur of abstract board games.  In it, he argues about concretely defining the properties that make a ruleset fun.

Unlike standard board games, abstract games are usually lacking in a tie-together theme.  This can be a barrier to enjoyment for some because players are not immersing themselves the role of a megalomaniac field general or a real-estate cartel in Atlantic City.

What, then, is so attractive about abstract games?  Nick references an article by J. Mark Thompson about what properties of good abstract games.  Nick then adds his own property, speciousness, a False Clarity about good strategies.  From Nick's post:
The greatest games pull this trick over and over – just when you think you’ve learned everything, the scales fall from your eyes yet again, and yet again you realize the game isn’t quite what you thought it was. And then, even after you know better, you’re sometimes tempted to make suboptimal moves because they just feel so right.
This goes beyond a standard of computational hardness and connects with a more psychological aspect. 

My inclination is that speciousness is more common with partisan games than impartial.  Hmmm.  Go enjoy Nick's full explanation to see some examples and follow his thoughts.