The court outlined the five criteria on which assessments of eyewitness identifications should rest: (1) certainty, (2) view, (3) attention, (4) description, and (5) time. The current study postulated that certainty has a qualitatively different from role from the four other Biggers criteria in assessments of eyewitness identification testimony. Specially, the research hypothesized that participants would ignore reports on other criteria when certainty was high, but not when certainty was low. The 386 participants were students at a large midwestern university. They read a fictitious trial transcript that manipulated three of the five Biggers criteria (certainty, view, and attention or certainty, description, and time). Each participant completed a questionnaire. Results did not support the certainty-trumps hypothesis. Instead, the Biggers criteria combined only as main effects, not interactions, thereby supporting a summative hypothesis. A surprising finding was that collateral effects indicated that manipulations of one criterion (e.g., certainty) affected perceptions of other criteria (e.g., attention and view) and vice versa. Findings indicated that people are willing to consider a variety of variables, even when the eyewitness is certain. Tables, appended table, and 31 references (Author abstract modified)