This document summarizes four ways ("BLIS") to collect data on personality: Behavior (B), Life Outcomes (L), Informants (I), and Self-reports (S). Each type of data has advantages and disadvantages. It is important to collect multiple types of data to get a full picture of personality, as each type provides only clues that are ambiguous. The document discusses the advantages and disadvantages of each data type and emphasizes that more data is generally better than less data when trying to understand personality.