This table shows the effect of sound (song and tones) on female birds. However, I'm not sure what the labels (F1 22, P and η2) mean. I've seen the labels on other tables too.

table (from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3508516/)

If anyone could help I'd be very grateful :)



1 Answer 1


F(1,22) is the result of an F-test with degrees of freedom 1 and 22, in this context most likely this is an F-test in the context of ANOVA; for the meaning of those degrees of freedom I would suggest further reading on ANOVA. Specifically, in this table it looks like we have a 2x2 ANOVA: with stimulus songs or tones and treatment E2 or none, and the interaction between them.

P is the P-value associated with that F-test; it is the probability of observing a result as extreme or more extreme than the F-test gave in this circumstance, given the null hypothesis was true (typically the null hypothesis is something like "the groups don't differ"), and assuming all of the assumptions of the statistical test hold true.

η2 is read as "eta-squared" - it is a measure of effect size, meaning it describes the magnitude of an effect controlled for some other characteristics of the measure, typically the variance. Many statisticians prefer presentation of effect sizes rather than p-values. A large value of η2 means that lots of variance in the outcome variable is explained by the parameter of interest.

  • $\begingroup$ brilliant answer $\endgroup$ Apr 17, 2018 at 18:27

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