Subjective characteristics in product design

Research by P.K. Kannan

At the Smith School, collaboration across functions and disciplines is common, but so is collaboration with business practitioners, who bring real-world problems for real-world solutions. For example, recent research by P.K. Kannan, Harvey Sanders Associate Professor of Marketing, with co-authors Lan Luo, University of Southern California, and Brian Ratchford, University of Texas-Dallas, could change the way manufacturers design their products.

Kannan had a long-term research relationship with tool manufacturer Black and Decker. In the process he discovered that it isn’t enough to just think about a product’s objective features, like price or weight. When consumers buy products, they are also considering subjective characteristics like comfort and effectiveness, which can’t be measured as easily.

Although companies consider subjective characteristics in the process of product design, no formal model existed to help designers account for the impact of subjective characteristics. Kannan and his co-authors developed a model that helps product designers understand the relationships between objective attributes and subjective characteristics, and how both jointly influence consumers’ purchasing decisions. This allows design engineers to gauge more accurately how consumers will respond to a product’s design.

Kannan and his co-authors applied the model to data collected jointly with Black & Decker in the development project of a new power tool. To see if the model was valid across product categories, they conducted a second study in the toothbrush category. (To do so they surveyed Smith School undergraduates. Good news—they brush their teeth!)

A consumer’s perception of a subjective characteristic like heaviness is dependent on a complex set of factors that varies from person to person. “When I tell you the weight of a product, you and I both understand what that is,” says Kannan. “We can measure weight, or memory capacity in a computer, or power in amps. But even though weight is an objective attribute, the feeling of heaviness is a subjective attribute, and those attributes influence a consumer’s decision to buy a product.”

The perception of a subjective characteristic like heaviness is so difficult to measure because it varies from person to person, regardless of a tool’s objective weight. A consumer with smaller or weaker hands may perceive a tool as heavier than a person with bigger or stronger hands.

One subjective characteristic may affect consumer perception in other ways as well. When people hold it in their hands, if a tool feels heavy a person may perceive that the tool is more powerful. So the objective attribute of weight then affects the perception of a tool’s effectiveness, its ability to do the job for which it was designed.

The model uses data gathered from consumers who compare several customer-ready prototypes of a potential new product design, and incorporates their ratings with additional data on subjective characteristics. The model views each prototype as a specific combination of objective attributes like shape and weight (plus price). As the combinations of attributes vary consumers’ perceptions of the subject characteristics—like perceived comfort and perceived heaviness—change accordingly.

The expense of producing multiple prototypes has always presented a barrier to their use in the design process, however. Kannan suggests that information about different characteristics could be garnered from different models of products already on the market, or that virtual-reality representations could be considered as substitutes for physical prototypes. That would make the model feasible for practical application.

Kannan also believes that the model could be widened for use outside the small-tools industry across an entire range of consumer durables. Laptops are judged on subjective characteristics of heaviness or screen sharpness; these characteristics could also be modeled for potential new designs.

This kind of diagnostic information is also important for managers, allowing them to better position and promote a new product properly in the marketplace.

“Incorporating Subjective Characteristics in Product Design and Evaluations” was published in the Journal of Marketing Research. It was a finalist for the 2008 Paul Green Award and won the 2009 Don Lehmann Award from the American Marketing Association. The annual award honors the best dissertation-based article published in the Journal of Marketing Science or Journal of Marketing Research in the previous two years. Co-author Lan Luo is a former Smith School Ph.D. student. For more information, please contact P.K. Kannan.