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rabbott
Posts: 1649
Posted 22:05 Nov 06, 2014 |

One question on the preliminary test Tuesday produced very strange results. The second question asked which of two graph labelings are valid topological sorts. Most people in the first section got the right answer. Almost everyone in the second section got the wrong answer! The first is a valid topological sort. Second is not. This line from the second

 ([b{3}] -> e{6} -> [g{5}]),

labels e with a higher number than one of its sinks. That is not valid.

I don't know why so many people from the second section got that wrong. Of the 17 answers to that question, all but four claimed that the second graph labeling was a valid sort.

This question will count for two reasons. For one thing, most people in the first section got it right. Secondly, this is a trivial question. Getting it wrong means you weren't paying attention, not that the question was too hard.

Last edited by rabbott at 22:34 Nov 06, 2014.
mnava18
Posts: 86
Posted 22:09 Nov 06, 2014 |

well , we didnt exactly have the full time for this quiz. if you remember we only got 5 mins for this quiz. which had alot of us scrambling to pick random answers and not giving us the time to fully read each question

Last edited by mnava18 at 22:16 Nov 06, 2014.
rabbott
Posts: 1649
Posted 22:34 Nov 06, 2014 |

I'm holding the line here. Time is an issue when a computation is involved, but how long does it take to scan down the list of nodes and notice that a node has a larger label that one of its sink nodes or a smaller label than one of its source nodes? This question asks about applying a definition, not about doing a computation.

Last edited by rabbott at 22:36 Nov 06, 2014.
mnava18
Posts: 86
Posted 00:00 Nov 07, 2014 |

well , myself and the other people in my group had no idea how to read this in the first place. that coupled with the pressure of having to read and answer everything quickly  with the short time constraint was a recipe for disaster.  i myself spent about 3 mins trying to figure out what those lists ment and had to skip it and try to come back to it ( which we couldnt because of the time). it wasnt till one of the tutors explained it to my group afterwards that we understood how to read it  i didnt see any examples like that in the video or the notes , so i was lost when i saw it on the quiz. I wish i was familar enough with the material at the time to eyeball it that quickly , but i find myself reading things over and over again because it feels like ur trying to trick us in every question lol , so i overthink things sometimes on easy things.

Last edited by mnava18 at 00:12 Nov 07, 2014.