I have a survey that collects information about volunteer events including names. I want to run a report that gives me the number of individual participants within a date range. If a person has come to an event multiple times, I only want to count them once. From the example, I want the report to tell me that there were only 4 individuals, not 5 since 1 volunteer participated twice during this date range.
You could try something like this in your report's summary section: ${mainLayer | stats:"count,volunteer_name" returnDistinctValues:true}. The key part being returnDistinctValues to ensure you're only counting unique items.