The latest edition (3rd edition) of our A2 Complete Companion has an error on page 285. The two blue boxes under the heading ‘Truth’ are in the wrong order. It should be H1 is correct (There is something going on) first and then H0 (There is nothing going on) second). The true positive occurs when the truth is that H1 is correct and H0 is rejected (H1 is accepted). This is correct on page 106 of The Research Methods Companion, which is shown on the right.

Thank you Lynne Erasmus for pointing this out.