The current research focused on two questions. First, the current research investigated the similarity leniency hypothesis and the black sheep effect in both a student sample and an adult sample. The impact of gender and age on each of these phenomena were explored within the realm of juror perceptions of witness preparation and believability. Each sample received identical questionnaires regarding preparation of a defendant as a lay witness, believability of the defendant as a lay witness, and expert witness believability with characteristics associated with "hired guns". However, on the questions relating to the defendant as a lay witness, age and gender were added to the question stems. The results indicated that there were no clinically meaningful differences between the two samples or between those matched on age and/or gender and those not matched on age and/or gender. Second, the current study investigated the use of categorical items versus interval items with relation to believability of the defendant as a lay witness. Results show that several interval items were more precise than one categorical item. These findings are congruent with prior research and support the use of students in jury research and highlight the need for continued research in these areas.