Held Monday, November 13, 2000
Today we discuss exam 2.
- Exam 2 returned.
- I've written up some
notes on that exam.
Please read those notes!
- We'll spend much of today's class going over the exam.
- Yes, I'll give you time to read over my comments.
- Please don't discuss your grade with others.
- I'm still working on exam 1.
- I was up until midnight on Saturday and 1am on Sunday/Monday
grading exam 2.
- I'm guessing that it will take until Wednesday or Friday for
- I've written a
contract guaranteeing a
- I will create two forms of exam 3. You may take only one.
- One will be a closed book test held
in class. You will have class time (and, if necessary, lunch time)
to complete the exam.
- The other will be one of my standard take-home exam.
- We should think about when the next take-home exam (and in-class exam)
- Many of you have asked what to do next semester, particularly as its
- I encourage those of you who did well on this exam to go on to 152.
- I encourage first and second years who did well on the exam to consider
CS majors. (We have a surprising number of dual majors.)
- I encourage first-year women in the first category to consider doing
summer research with me. I'll try to contact you individually.
- I encourage all of you to come talk to me if you want to talk about
any of this stuff.
- Our grader, Greg Fuller, would like the URLs of your homework
4s. Send email to
- Exams returned. Pause for reading.
- General notes.
- Individual problems
- For each: Why did I write the problem?
- Basically four categories:
- Gets it and works incredibly quickly (a few)
- Gets it but needs some time (many)
- Having some trouble (more than I'd like)
= Didn't turn anything in
- I don't think poorly of those of you in the third category
- Not everyone can get this stuff (example: My wife)
- Perhaps we need to work together to resolve your problems
- My goal for every exam is that you learn.
- I hope you learn some things by doing the exam (including
the realization that you can actually do some of this stuff.)
- I hope that you learn some things from my comments (even when I
don't take off points).
- I hope that you learn some things from our discussion of the exam.
- I hope that you learn some things from
the notes on the exam.
- Some general comments:
- Learn to use
load. I didn't need to see the databases
included in your files.
- Format your code for readability. It's a pain in the whatever to
read code that is all left-justified or that wraps around.
- Comment your code. See below for more.
- Input is not a verb. Inputted is not a verb form. Imputted is
certainly not a verb form. A user enters input.
- Scheme is a proper noun and should be capitalized.
- I expect you to write well.
- Most of your procedures need the six Ps (and also require that you
think about the seventh P: problems).
- Procedure. The name. Try to use clear names.
- Parameters. Direct input to the procedure. Should correspond to
the values in your lambda. (Also called Given.)
- Purpose. A short summary of what the procedure does.
You don't need to tell me how it does it; I can read code. (Of course, an
explanation of your code is also nice.)
- Produces. The value your procedure produces (the return value).
(Also called Result.)
- Preconditions. Things that have to hold in order for
your procedure to work. Typically, preconditions describe the form of
the parameters, the existance of other procedures or variables, or
behaviours of the user. (I suppose this could also be called
- Postconditions. Things that you can guarantee when your
procedure is done and all the preconditions hold. Typically, postconditions
say something detailed about the value produces. They may also say
about what happens to parameters (since every procedure is potentially a
mutator) and about input/output. (I suppose this could be called
- I only counted the first five problems, and made them worth 20 each. I gave
extra credit for the last problem.
- I wanted to see sample output!
- There were some very similar very strange answers. Please be careful not to
use other people's work on your take-hom exams.
- UGH means that your code was pretty damn ugly at the point
- Needed better error checking.
- I expected to see good argumentation strategy (including predicting
- Many of you could have used some careful editing.
- I found it interesting that some of you described the purpose of the procedure
if, as in ``If the two people are the same, returns true.''
- I was trying to compare the given code to
which I see much too often.
- Yes, you could write too much for this problem.
- I found it amusing that even after this problem, some of you wrote things
- I wasn't thrilled with the number of calls to
- Notes on
- I'm not sure why you found this so hard.
- We'll go through it step by step and then discuss key issues.
Thursday, 24 August 2000
- Created as a blank outline.
Sunday, 12 November 2000
Monday, 13 November 2000
- Posted to Web.
- Updated slightly.
Back to Vectors, revisited.
On to Notes on exam 2.