Mael's taxonomy of biodata item attributes is applied to two biodata instruments in order to investigate the relationship between item attributes and (1) validity and (2) socially desirable responding. The results show a strong relationship between item attributes and validity, with items that are more historical, external, objective, discrete, and verifiable and less job relevant displaying stronger validities. Weaker relationships are observed between the item attributes and socially desirable responding. Implications of these results for building a “clearinghouse for documentation of objective biodata items” is discussed.