0

I have two algorithms, $A_1$ and $A_2$.

  • $A_1$ either accepts or rejects samples from dataset $P$
  • $A_2$ either accepts or rejects samples from dataset $Q$

Below is a 2x2 contingency table for the number of accepted and rejected samples by $A_1$ and $A_2$ on their respective datasets:

enter image description here

i.e $r_P$ is the number of samples rejected by $A_1$ on dataset $P$, $n_P$ is the number of samples in $P$ and similarly for $r_Q$ and $n_Q$.

I would like the determine if $A_2$ is statistically more likely to reject samples in its dataset compared to $A_1$.

My first thought was to use fisher's exact test as suggested here. But upon learning more here I see that the null hypothesis for fisher's exact test is not suitable and I instead need to use Boschloo's exact test. The only problem is the scipy Boschloo requires something called simplicial homology global optimization which is extremely slow for large sizes of $n_P$ or $n_Q$.

I'm wondering first if Fisher's test is indeed not suitable for this situation? And second what a good exact test to do here is (since my samples sizes may not be large I would like the test to be exact). I'm also only concerned about the one sided alternative i.e $r_Q> r_P$

user2757771
  • 131
  • 1
  • 3
  • 1
    You can still use Fisher's exact if the margins are not fixed in advance, see [this post](https://stats.stackexchange.com/questions/441139/what-does-the-assumption-of-the-fisher-test-that-the-row-and-column-totals-shou). – philbo_baggins Jan 11 '22 at 18:18
  • While I agree with the points made in Gordon Smyth's answer linked by philbo_baggins above (indeed I have made similar points in several answers myself), it looks to me like your alternative hypothesis is directional: "*I would like the determine if A2 is statistically more likely to reject samples in its dataset compared to A1*", which would change things somewhat, if that's indeed what you seek to test. – Glen_b Jan 12 '22 at 09:19
  • @Glen_b Yes, this is what I seek. Can you elaborate – user2757771 Jan 12 '22 at 20:56

0 Answers0