Publication Date



Open access

Embargo Period


Degree Type


Degree Name

Doctor of Philosophy (PHD)


Marketing (Business)

Date of Defense


First Committee Member

Caglar Irmak

Second Committee Member

Juliano Laran

Third Committee Member

Claudia Townsend

Fourth Committee Member

David Faro


This dissertation examines how the context in which consumers encounter products shapes perceptions of product efficacy and product efficacy experiences. Contextual influences are recognized as relating to both the product and the consumer. While extant research on product efficacy perceptions has examined a range of factors inherent to products that influence perceived efficacy, less research has examined how the context in which a product appears influences product efficacy judgments, and even scarcer is research on the influence of a consumer’s decision context. The present research advances knowledge in both arenas by studying two practically important and theoretically-driven contextual influences on product efficacy—one relating to the product, and one relating to the consumer. The first essay (Chapter 2) examines the context in which a product appears, focusing on the presence or absence of product replicates in product presentations. Although products appear both in isolation and as groups of replicates in a range of marketplace settings, previous research has not examined how this impacts product evaluations. The present research fills this gap, demonstrating that a product is perceived to be more effective when presented as part of a cohesive group of product replicates (vs. in isolation) because such groups highlight the underlying essence of the products and thereby increase attention to product efficacy. The second essay (Chapter 3) studies a common contextual influence on consumers: experiences involving low (vs. high) personal control. Two studies demonstrate that individuals feeling low (vs. high) personal control perceive greater product efficacy. This effect is driven by the motivation to use external sources of control that can help reestablish a control-deprived consumer’s own (internal) sense of control; as such, low control increases the perceived efficacy of products that can help a user reach a desired outcome, but does not impact the perceived efficacy of products that are personally irrelevant for restoring control at the time of judgment. The dissertation concludes with a discussion of the theoretical and practical implications of the present research, as well as limitations and directions for future research.


product efficacy; product effectiveness; contextual effects; product quantity; psychological essentialism; personal control