Arnold Rosenbloom
arnold@cs.toronto.edu http://www.cs.toronto.edu/~arnold 
Problem Solving 
Level  What you did 

5  Reason, apply, problem solve, present: Correctly applies ideas to reach a clear, concise, correct, cleanly presented solution. Can reason about ideas presented. Can apply them to different settings. etc. Minor technical flaws allowed. 
4  As in 5 but lacks some clarity, not as concise as possible, some minor flaw, not a clean presentation. Not clearly explained, does not highlight key concepts. 
3  Semantics: Demonstrates correct understanding of basic definitions, ability to correctly apply basic techniques, theorem statements etc. 
2  Some major flaw in the understanding of basic definitions, techniques, theorem statements. Examples are: Applies theorems to wrong settings. Does not understand the goal (ie tries to prove the wrong result). Solves the wrong problem. 
1  Syntax: Ability to restate given definitions, theorems, techniques. 
Level  Question Type  Example 

5  Choice of tool is not clear  How many zeroes at the end of 999! 
3  Solution involves direct application/understanding of tool. They know which tool to use.  Use for loops to print out

1  Solution involves memory.  Write a for loop that prints the numbers 20 to 50 
A locker room has lockers numbered 0,1,2,...,1023. All lockers are initially closed.
Level 3 solution, Level 4 solution (no explanation given). Note the flaw at 0 in both cases.
Prove that eventually some person will be holding two cards with the same number on them.