As the number and variety of products in stores increases, fielding a conjoint study on a computer screen gets more complicated. And, you don’t want to fatigue your respondent with options that don’t even interest them. That’s where evoked set steps in.

In the December 2015 edition of Quirk’s magazine, SKIM’s quantitative experts share how the use of evoked sets requires a considered approach to experimental design along with analysis expertise. One can construct respondent-specific consideration sets, understand the trade-offs within those sets, and build on those to create a full understanding of marketplace dynamics.

Using evoked sets conjoint to model consumer choices

“Conjoint analysis is a frequently-used methodology for understanding how consumers manage trade-offs during the decision-making process. For example, how will consumers respond if we offer a larger size at a slightly higher price? Will my new product cannibalize sales from my existing portfolio or draw sales from competitors’ products? What if I change the price again? What if my competitors change their prices, sizes, offerings? These are just some of the questions addressed by a conjoint study.

In some cases, we want to examine these consumer trade-offs in a larger competitive space. For example, we may want to understand the market dynamics among hundreds of products with different sizes and prices. Think about the number of soft-drink options or the number of snacks possible. This might include those at your local store, along with many other potential products.

Our ability to program conjoint surveys has improved significantly in the last decade and today we can show respondents realistic simulated shelf sets with many products on a computer screen. But a computer screen is not the same as a store. As the number of products increases, the number of items to put on a computer screen becomes a challenge. And at a certain point the scope of the project becomes unwieldy. Confronted with the limitations of screen real estate in a conjoint survey, one of the alternatives is to use something called evoked sets.

For any given consumer there is a smaller subset of products from which they actually make trade-offs. That’s what makes evoked sets possible. For any individual respondent, many of the products available are simply not in their consideration set. In the soft-drink market, for example, each consumer usually buys from a narrowed down list of brands, flavors and pack sizes despite the fact that there are hundreds of options to choose from. Of course the specific set of items in a consideration set differs across respondents. Evoked sets build on this idea by first finding out what products make up a specific respondent’s consideration set and then building a custom conjoint task. For respondents, it’s like walking into a store with a subset of products customized just for them…”

Read the entire article on Quirk’