Date of Award




Document Type


Degree Name

Doctor of Philosophy (PhD)


Department of Psychology


Industrial/Organizational Psychology

Content Description

1 online resource (xiv, 249 pages) : illustrations (chiefly color)

Dissertation/Thesis Chair

Michael T Ford

Committee Members

Kevin J Williams, Zheng Yan


Difficulty, Experience, Resources, Situation, Support, Tenure, Achievement motivation, Motivation (Psychology), Goal (Psychology), Performance, Intrinsic motivation

Subject Categories

Business Administration, Management, and Operations | Psychology | Social Psychology


It seems a self-evident truism to many that performance at school and work is determined by the extent to which one "can do" and one "will do" the task effectively. Grounded in this logic, research, practice, and textbooks in industrial-organizational psychology over the past 60 years have supported the notion that performance is a multiplicative function of ability and motivation, such that P = f(AXM) (where P = performance, A = ability, and M = motivation). In this study, I addressed four issues surrounding this multiplicative model. First, I began by exploring whether and when multiplicative (versus simpler additive) models should be considered. Second, I provided arguments in favor of a multiplicative model and conducted literature reviews. Third, I advance a more complete operationalization of the ability and motivation factors by introducing "task capability" (collectively, knowledge, skills, and abilities) and "motivational effort" (direction, intensity, and persistence), respectively. Finally, I hypothesize three moderators of model support that have not yet been researched: task difficulty, experience, and task-enablers. A test of the one omnibus and three moderator hypotheses was conducted using 945 psychology research pool respondents. Motivational-effort and components of capability were collected through self-report questionnaires, administered to participants during the course of the fall 2013 semester. Performance and SAT scores (a proxy for ability) were captured shortly thereafter from official student records after the completion of the fall 2013 semester. Motivation and capability were found to interact in the expected pattern. This interaction was found to vary in strength based on experience and the presence of task critical resources, although these patterns were not always as hypothesized. The size of the interactions was much smaller than expected, raising power issues, and calling into question the practical validity of multiplicative over additive models. Given the added challenges surrounding multiplicative models, and the modest effect sizes, I suggest additive models are most frequently more appropriate. Future directions for research and theory are discussed.