Ok, so I haven’t emailed the TA at all yet. I’ve finally gotten my grades back and I’m sitting on this gem of a response. Let the advice flow!

I have questions about the grading of my homework 1 for CS570. I have compared my answers to the answers provided in the solution and I need help understanding where and why I had points deducted.

Problem 1.4: Our algorithms appear functionally equivalent. I received a 15/25.

Problem 1.7: Our algorithms appear identical. I received a 20/25.

Problem 2.6: Our algorithms appear identical. I received a 15/25.

Problem 2.7: My algorithm has a superior running time to the one provided. I received a 15/25. I also do not understand how the solution provided is accurately mapping the growth rate of the song.

Is it possible for me to get detailed explanations on why each of my solutions received the score it did?

My homework was submitted via DEN. If you need another copy I can provide it.

Most of this can probably be explained by the stuff from the other thread about proofs and runtimes, but the 4th one is a real sticker. His algorithm was wrong and his runtime was higher than mine, and he gives me a 15/25? I have to be missing something here - the class average was an 88% including that problem.

I’ve never met him! This is the first assignment, I’m taking the class online, and there are 3 TAs :P

The one who graded it wasn’t even the one who told me I couldn’t resubmit. If he’d given me a B I might have swallowed it but this is harsh. If I don’t finish with a B then I don’t get my transfer credit, don’t finish my MS, and I’m short $4000 for nothing. I will not sit back and watch if this keeps happening.

So email, and ask. Before you start screaming conspiracy and “I payed so much for this class”, find out why. Was your code hard to follow? Are you sure that it was correct in all cases?

Yeah I’m not going to mention the money. I was pissed when I composed that original email and that’s why I put it on Qt3 instead of emailing him. I’m trying to be cool about this, I just can’t afford to get fucked without at least being told why so I can dodge next time.

It’s alawys reasonable to ask a TA for a detailed explanation.

Although, if I were going to argue that his answer is wrong, I’d probably want to provide some sort of proof, not just a flat assertion. (It’s hard to tell without being given the question or answer). Not that TAs or professors are never wrong–I remember a test where the main problem was insoluble, b/c the professor hadn’t bothered to solve the problem before he set it in a test–but they’re more likely to take you seriously, and possibly even up your grade for seeing the problem.

Also, take heart–at 2-4% of your grade, it’s not that big a deal even if the TA doesn’t change his score, you can still pull out of the hole pretty easily.

I have a spreadsheet ready if he doesn’t see his error on the 4th question.

The problem is to analyze the minimum script length to store songs similar to the Twelve Days of Christmas, e.g. songs where each verse is equal to the previous verse plus one new line.

His analysis is that a song with n words can be encoded in O(n/k) space, where k is the number of initial lines. Mine is that it is encoded in O(sqrt(n)) space.

The twelve days of christmas has v=12 verses, k=2 (on the first day of christmas/my true love gave to me), and 102 lines.

The actual script is 14 lines long (k + 1*v). n/k = 51, sqrt(n) = 11.

At v=1000, script length is 1002. His n/2 = 252756. My sqrt(n) = 710.

At v=10000, he is off by 250,000%, I am off by -30%.

I am hoping I don’t have to show this to him.

But yeah, I can eat 4%. I just need to get things settled down so that I can be sure I’ll make As on future assignments if I’m solving the problems correctly. As soon as I’m sure I can make an A I’ll be happy, regardless of the work involved.