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Strange change of the precision@k

Open liushunyu opened this issue 6 years ago • 4 comments

Hello! When I run the model of dynAE, using the dataset of "SBM", I get the result below.

P@2 P@10 P@100 P@200 P@300 P@500 P@1000 P@EdgeNum 0.000000 0.000000 0.100000 0.650000 0.770000 0.826667 0.876000 0.924000 - 0.000000 0.000000 0.100000 0.580000 0.755000 0.810000 0.868000 0.919000 - 0.000000 0.000000 0.000000 0.560000 0.730000 0.796667 0.864000 0.917000 - 0.000000 0.000000 0.000000 0.830000 0.895000 0.926667 0.946000 0.963000 - 0.000000 0.000000 0.100000 0.750000 0.835000 0.883333 0.922000 0.953000 -

I can't understand: 1. why the P@2 and the P@10 would always be zero? 2. why the P@k will decrease with increasing k?

We know that precision@k is the fraction of correct predictions in the top k predictions, so the result above is strange !!!

liushunyu avatar Mar 08 '19 14:03 liushunyu

Hi, if you run the above experiments multiple times and take an average you will get the results you desire. The discrepancy you are seeing is because of stochasticity. Since p@2 only looks at top 2 links, it can only take values of 0, 0.5 and 1 in a single run.

palash1992 avatar Mar 10 '19 02:03 palash1992

Ok, you answer my first question, as you said, the zero value of P@2 is because of stochasticity.

but the second question?why the P@k will decrease with increasing k?

liushunyu avatar Mar 10 '19 03:03 liushunyu

Are you saying why is P@k increasing with increasing k? Not the other way round right?

palash1992 avatar Mar 14 '19 03:03 palash1992

Are you saying why is P@k increasing with increasing k? Not the other way round right?

oh, yes

liushunyu avatar Mar 14 '19 04:03 liushunyu