Quiz 4 - Questions I & VI

Quiz 4 - Questions I & VI

par Nicolas Quentin M. Mahiat,
Nombre de réponses : 2

Hello,

I have two remarks about the correction of the quiz 4:

  • For Question I.3, we are asked to "Indicate which of the following constraints should be enforced for the stochastic grammar G2 so that the most-probable parse is making use of the rule...". In the correction, you mention that p2 < p1 · p6 is a solution because it implies p2 · p5 < p1 · p6. But p2 < p1 · p6 is not necessary (e.g. p1=0.6, p2=0.5, p5=0.5, p6=0.6 satisfies p2 · p5 < p1 · p6 but not p2 < p1 · p6), so it should not be enforced, but it could be.
  • For Question VI, I do not understand how the proposition "Each component of <d3> is strictly larger than the corresponding one in <d1>" can be true given that some components of <d1> and <d3> are 0 because tf(t,d1)=tf(t,d3)=0 for some indexing terms t (and probably many) that are not in the document.

Thank you in advance for your answer!

En réponse à Nicolas Quentin M. Mahiat

Re: Quiz 4 - Questions I & VI

par Jean-Cédric Chappelier,

Q3 : you are perfectly right (except in your example, where p1 + p2 do not sum up to 1); the wording used for Q3 should indeed rule out the sufficient but not necessary condition.
However, only 7% of the class answered that and 56% of the class (!) selected the sufficient but not necessary condition (and nobody selected the two).
Since our main goal with that question was to test knowledge about stochastic coefficients, we decided to grant points to both answers; BUT the way it has been set up is indeed unfair to the 7% who correctly answered.
I thus now fixed that manually, as there is actually no way of doing this automatically in Moodle.

Regarding Q10: you're also right and the wording of the Q10 should have been:

> Each non zero component of <d3> is strictly larger than the corresponding one in <d1>

But, as already mentioned in my former post, we already dealt with Q10 by computing the grade as a fraction over 26 points (instead of 30). In addition, I also reconsidered manually the few cases with only one good answer.

Thank you for your relevant questions.

En réponse à Jean-Cédric Chappelier

Re: Quiz 4 - Questions I & VI

par Nicolas Quentin M. Mahiat,

Thank you for your answer and for granting the points!

Indeed, I forgot the additional constraint p1 + p2 = 1, I should have said p2 = 0.4 to be correct.

Have a nice Christmas break!