RESEARCH PAPER The First Twenty Years of the Will and the Ways: An Examination of Score Reliability Distribution on Snyder’s Dispositional Hope Scale Chan M. Hellman • Megan K. Pittman • Ricky T. Munoz Published online: 9 May 2012 Ó Springer Science+Business Media B.V. 2012 Abstract C. R. Snyder has established hope theory as an important contributor to positive psychology. As the empirical evidence continues to grow, hope researchers need to have confidence that their measures will produce reliable scores. This study presents a reliability generalization on both the internal consistency and test–retest reliability esti- mates from Snyder’s dispositional hope scale. While over 300 published works were found to have cited the target article 74 present internal consistency scores and 17 reported scores for test–retest reliability. The results of the reliability generalization suggest support for the score reliabilities produced by the dispositional hope scale. However, internal consistency was higher for studies using the eight-item response format (a = 0.82) compared to those using the four-item response format (a = 0.77). Additionally, the test–retest score reli- ability was high 0.80 with no statistically significant differences by response format. Findings also demonstrated that score reliability estimates were not significantly influenced by the coded sample characteristics. Keywords Dispositional hope Á Reliability generalization 1 Introduction Approximately 20 years ago, C. R. Snyder introduced a theoretical framework of hope along with a dispositional measure of hope (cf. Snyder 1989; Snyder et al. 1991a, b). Snyder et al. (1991a, b) defined hope as ‘‘…a cognitive set that is based on a reciprocally derived sense of successful (a) agency (goal-directed determination) and (b) pathways C. M. Hellman (&) Tulsa Schusterman Center, Department of Human Relations, University of Oklahoma, 4502 East 41st Street, Tulsa, OK 74011, USA e-mail: chellman@ou.edu M. K. Pittman Center of Applied Research for Nonprofit Organizations, University of Oklahoma, Tulsa, OK, USA R. T. Munoz Anne and Henry Zarrow School of Social Work, University of Oklahoma, Tulsa, OK, USA 123 J Happiness Stud (2013) 14:723–729 DOI 10.1007/s10902-012-9351-5