Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)

Legacy Department

Mechanical Engineering

Committee Member

Dr. Georges Fadel, Committee Chair

Committee Member

Dr. Mary Elizabeth Kurz

Committee Member

Dr. Joshua Summers

Committee Member

Dr. Gregory Mocko

Committee Member

Distinguished External Reader: Dr. Kemper Lewis, SUNY at Buffalo, NY


Designers can benefit from involving the user in the product development process. Understanding how users perceive products can help designers make decisions that better accommodate user needs. Though several methods have been created that involve the user at different stages of the design process, there is still no clear connection between user perceptions and product improvements. Affordance Based Design (ABD) provides the theoretical background needed to explore such connections. ABD is a systematic de-sign method that uses the concept of affordances to describe the interactions between users and products. The integration of ABD and genetic algorithms (GAs) is proposed as a way to capture the perceptions from users in the form of affordance quality evaluations. This research investigates how those user perceptions can be used to improve or evolve product variants. A design tool is developed to test product evolution with the proposed ABD/GA integration. The affordance based interactive genetic algorithm (ABIGA) lets designers capture user perceptions of products. In this tool, designers must specify the design pa-rameters of the product as well as some of its affordances. Users can access design exper-iments from their computers or smart phones and are shown a representation of the prod-uct they evaluate. A set of six experiments were carried to test the evolution of a steering wheel. Three of these experiments were done with real users while the rest were done us-ing a random number generator as the input. Two additional experiments were done with real users to test the evolution of a compact digital camera. Results show that product form can be evolved toward better solutions based on the perceptions of users. The results can also link user perceptions with the form of the product. Designers can extract relationships between affordance evaluations and design parameters. Such relationships can be used to predict how changes in the design parameter values can affect user percep-tions of affordance quality. Product evolution through affordance evaluations could eventually be used to not only improve the external geometry of products, but also certain internal aspects of prod-ucts. Such a tool could be used in multiple stages of the design process, taking advantage of optimization tools linked to the concept of affordance to automate aspects of the prod-uct development process. (33756 kB)
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