Confusion reigns about the meaning of “population” or “case” and when to use N and n.
I find unclear (if not contradictory) guidance due to wiggle room in the explanations. For example, the APA 6th edition refers to N and n as “cases” and not (for example) as only breathing or once-breathing humans or animals via direct reference (children) and indirect reference (households).
Studying the examples in the APA manual, I see occasional examples of n, but none of N (as best I can tell, N is mentioned only in Table 4.5 as “Total number of cases). So the first question is “what does ‘cases’ mean? Is it only participants, whether willing (humans) or unwilling (corpses, animals)?
Or can N refer to the number of questions in an instrument, and n refer to the number of questions that rate one score vs. another?
Example: Survey has 24 questions; 17 of 20 participants rate 15 questions as 4 or 5 on a 5-point scale (median 3.5 or higher).
Under what circumstances, if any, would you state N = 24, n1 = 15, and n2 = 9?