By traditional definition, reference involves a patron with an information need, a tool or source, and library staff with expertise.   Reference is a way to capture the value that library staff add to a community that a patron doesn't get in a big bookstore.  Remember that the point of this whole survey thing is having a accurate tool to aid in advocacy and fund raising. 

Reference encompasses the smaller questions library staff answer, as well as their teaching role, and role in matching people to desired literature.