Product form and aesthetics play a major role in consumer preference and product differentiation. During product family design, it is important to differentiate products in the family yet similarities among some stylistic features may connote a more coherent design strategy. Shape grammars offer a method for producing designs with a coherent style along with the ability to control the variation of the output shapes. In this paper, we investigate the use of shape grammars to support product family design, namely, identification of features that shape the perceptions of similarity within a family. A survey-based approach is implemented wherein the impact of a shape parameter on product style is evaluated by comparing design variants to a baseline design. Respondents are asked to rate the style similarities on a Likert-like scale, and candidate shape parameters are screened for aesthetic significance using a fractional factorial experiment. The approach is demonstrated using a family of medical ultrasound transducers, and our screening is validated using a full factorial experiment with practicing ultrasound transducer designers and engineers.