When COUNT or SUM are used as output in an Ad-hoc query, the count or sum turns out incorrect
COUNT and SUM work correctly when you use criteria that always has one value, such as Inactive, Deceased, or Is Organization.
But one constituent can have many addresses, and many donations. So Address and Donation amount are examples of one-to-many fields in a constituent query (one constituent, many values). COUNT should not be used when there are one-to-many fields. Instead, use a Smart Field to work with constituent donation amount.
Steps to Duplicate
1) Create a Constituent query 2) Add some criteria, including Address 3) Place COUNT(NAME) as the output. 4) Note that the Count is incorrect