Despite advances in the scientific methodology of witness testimony research, no sound measure currently exists to evaluate perceptions of testimony skills. Drawing on self-efficacy and witness preparation research, the present study describes development of the Observed Witness Efficacy Scale (OWES). Factor analyses of a mock jury sample yielded a two-factor structure (Poise and Communication Style) consistent with previous research on witness self-ratings of testimony delivery skills. OWES subscales showed differential patterns of association with witness credibility, witness believability, agreement with the witness, and verdict decision. Juror gender moderated the impact of Communication Style, but not Poise, on belief of and agreement with the witness. Results are discussed with attention to application of the OWES to witness research and preparation training.

Self-Efficacy Theory (SET; Bandura, 1986, 2000) has generated research and practice ramifications across areas of psychology. However, self-efficacy has yet to be assessed in a legal context. The present paper juxtaposes self-efficacy with self-confidence in terms of theoretical foundations and practical implications, with attention to the area of witness testimony. It is concluded that the concept of witness self-efficacy possesses thorough theoretical grounding as a potential target for witness preparation. As such, we put forth an integrated model of witness preparation featuring self-efficacy bolstering techniques within an established witness training framework.

Despite the application of Self-Efficacy Theory (Bandura, 1977, 2000) to many areas of psychology, there is a lack of research on self-efficacy in the ability to testify in court. The present study fills this gap by incrementally developing the construct of Witness Self-Efficacy and establishing its psychometric properties. Study I featured exploratory and confirmatory factor analyses yielding a two-factor Witness Self-Efficacy Scale (WSES). The two components are Poise and Communication Style. Study II used a second data collection to show that both WSES domains possess convergent, divergent, and predictive validity relations consistent with those expected using an SET framework. Notably, WSES components predicted perceptions of witness credibility and sentencing outcomes above and beyond witness extraversion, general self-efficacy and general self-confidence. Implications for SET and witness preparation training are discussed.