1. It Seemed Like a Good Idea at the Time… Katherine Deibel University of Washington

2. It was a dark and stormy night at the University of Washington… 90 minutes until latest Data Structures project was to be turned in… I was the graduate TA… drizzly

3. My apartment, 10:30pm… Nursing the aches of a first year graduate student course load… Undergraduate TA handling the turnin at midnight… I decided to check e-mail one last time before bed…

4. Students could not log in… programs were freezing… I contacted a student by IM… I realized I had to handle this personally… CHAOS! PANIC!

5. Undergraduate lab, 11:00pm… All students were panicking … I managed to find a terminal with ‘top’ running… I yelled for my students to terminate their programs… It was too late…

7. I got to bed about 1:30AM

8. So What? An assignment crashed a server… big frickin’ deal right? But this assignment had been used before with no problems… What was different this time?

9. The Programming Assignment Word Frequency Analysis Tool: Implement an unbalanced BST, AVL tree, and a Splay tree where a node represents Extra Credit: Use gprof to profile your three trees. Run your trees on two inputs: Any file from Project Gutenberg The provided file: words.txt a.k.a. The Unix Dictionary

10. Let’s Do The Math… Unbalanced BST + 45,424 ordered words = BAD (1) (1) + code profiler running = MORE BAD(2) (2)  >6 instances running on the same server = REALLY BAD (3) (3)  all instances running at same priority = SERIOUSLY REALLY AWFULLY BAD

11. Again… So What? The lesson is Use a smaller file next time or Teach the students to use ‘nice’ True, but… This had not been a problem before Some students successfully profiled their code Again, what was different? Something motivated more students to do the extra credit than in previous course offerings

12. A New [Better] Grading Policy Joint decision and effort by myself and the undergraduate TA Both of us graded the assignments I graded the theory side: Correctness, Complexity Generalizability Hannah graded the software engineering side: Programming style Documentation

13. What This Change Meant Before: Summative assessment Surface grading of code Few grader comments Correctness most important element Style worth 1-2 pts Programs worth 20 pts Perfect scores common Now: Formative assessment Deep grading of code Many grader comments All elements weighed equally Style worth 20+ pts Programs worth 80+ pts More points lost Students panicked about grades!

14. The Mystery Solved We failed to emphasize Non-perfect scores were expected Performance would be curved Students leapt at chance to recover points More students doing extra credit More strain on undergraduate servers

15. Our Mistakes: Redux Provide too large of an input file Should have taught students about ‘nice’ Changed grading policies without addressing underlying student culture about grades and points Checking my e-mail that one last time before bed