The current study sought out to advance the Social Self-Efficacy and Social Outcome Expectations scale using multiple approaches to scale development. Data from 583 undergraduate students were used in two scale development approaches: Classic Test Theory (CTT) and Item Response Theory (IRT). Confirmatory factor analysis suggested a 2-factor structure that aligns with the theoretically based domains for SEOES items and supports previously proposed models of this scale from CTT and psychometric analyses. The IRT analysis indicated that the SEOES items have greater measurement precision at measuring lower levels of the latent constructs. Future research directions are provided and practice implications are discussed.