Ken,
>I have a report I'm doing on students. On the group footer line I have their average score, lowest, and highest score. I'm trying to count the number of students who passed (field passfail = "YES"), and failed (field passfail = "NO ") . What I'm getting is the total number of students in each age group. I place the field on the report, go to properties, place 'passfail.passfail= "Yes"' in the expression, go to calculations, select count, reset when age changes.
You need SUM, not COUNT, and your expression should evaluate to a numeric value, so you could make it IIF(passfail.passfail='YES', 1, 0). I did not take time to test this before posting, so let me know if it does not do the trick.