Hochberg/Bonferonni correction for multiple one-sample t test I am trying to conduct a content validity analysis where I want to test if a certain item (e.g. a question) can be related to a certain construct (e.g. depression). I've let people fill in a questionnaire, asking them if they would assign an item to a construct and with how much certainty (0 - 100%). I've got my data, did the processing and executed a one-sample t-test for every combination item - construct.
For example I test, does the participants average value for item 1 related to construct 1, significantly differ from 0 (there is a positive linkage). I do this for every item & construct combination. I have 20 items & 7 constructs; thus execute 140 t-tests.
A paper suggested correcting my p-values with a bonferroni or hochberg correction because I've performed multiple tests.
From what I understand a correction looks at an amount of tests to reduce the 'familywise error rate'. My question is, what is a family in my case? Is this 20 t.tests within a construct family, 7 t.tests within an item family or 140 t.tests within my combination of construct-item?

The definition of "Family" depends on the situation, and in some cases (yours) is somewhat ambiguous. The most important thing is to state what you did clearly. Since you didn't plan the analyses in advance, probably the fairest approach would be to use the most conservative approach, setting the family to all 140 t-tests.
