Session search

This is an additive search: what does this mean? For example, if you enter "Gray" as the last name, you'll search for all session with "Gray" as the speaker last name. If you then *also* choose grade levels 1-3 and 4-6, you will search for all sessions with "Gray" as the speaker last name and that are in grade levels 1-3 and 4-6. The more you enter, the more specific the search becomes!