As the organization determines which customers to serve, it must first divide the market into reachable portions, or of the market, and then select which portion of the market to target.

i believe the answer is: description

description refers to the goal of psychologist to identify the phenomenon that being observed. this goal is being actualized by collecting data/information from various clues that observed through the phenomenon. this goal must be accomplished before pyschologist able to create methods of treatment.