Marking comments for Project 1 -- by Alexander Kress

This project was marked in two stages. In stage one the code was put though
a large set of test cases that covered all aspects of the project. Attached
to the second page of the printout, that you will receive in class, is a
break down of the autotesting marks.The second stage involved marking the
project for style, documentation and testing.

To speed things up I mostly used codes to indicate the mistakes. Attached
you will find codes.ps [EJJ: see p1-marking-codes on the web page] file
listing these codes. Note that the points you see in this document are
nothing more than the most common errors, this is by no means a complete
list of what one should have to receive 100%.


Style and Documentation.

To get full marks for Documentation you needed to have preconditions and
description for every defined procedure. And as always, the code had to be
properly commented. I was not really expecting a lot of comments, however
when I saw a procedure with more than 10 lines of code and not a single line
of comments, that qualified as a mistake.

Also, note that a procedure description such as "helper1: this procedure is
a helper method for infix-to-prefix" does not really count as meaningful
description. A description has to explain the purpose of this piece of code,
which the above does not do.

In style one of the most common mistakes was to have an if statement that
looked like the following: "(if (statement) #t #f)". if statement here is
clearly unnecessary here since just saying "statement" would achieve the
same result.

Similar mistakes included

(and statement1 statement2 #t)
(if (statement) #f #t)
(eq (statement) #t)

For other style mistakes see the attached codes.


Testing

The testing categories in the codes file (1-8) are pretty much self
explanatory.
A missing test case in the Unit testing costs 1 mark, and 1/2 marks in the
system testing.

Most students did well on the Unit testing (not counting 1D). However, many
did not provide sufficient system testing.
Also there were a few submissions where the testing consisted of a bunch of
scheme calls with no explanations. In these cases 0 would really be a fair
mark since without explanation these cases are meaningless (part marks were
given, though).


Penalties

As was stated in the assignment you were not allowed to use set! anywhere in
your code. A small number of students who did use it lost 10 marks as a
penalty.


Bonus 1

Here the division of marks was: 2.5 for description, 2.5 for implementation.


Bonus 2

2 marks for description, 2 marks for implementation, 1 mark if autotester
reported 1/5 for set 20 (which basically indicates that your code was able
to handle at least some of the cases).

The bonus questions were done quite well. The most common mistake was
forgetting to check whether all of the code still works after adding the
bonus.