Which of the following is a technique used for customer segmentation in marketing research?

Perceptual mapping is a valuable technique used for customer segmentation in marketing research because it visually represents how customers perceive a brand or product relative to competitors based on specific attributes. This method helps marketers understand the positioning of their products in the mind of consumers, identifying gaps in the market and enabling more effective targeting of different customer segments based on their preferences and perceptions.

In contrast, the other techniques listed serve different purposes in research and analysis. Experimental design is primarily focused on testing hypotheses by controlling variables to observe potential outcomes; it does not specifically target customer segmentation. Regression analysis is used to understand relationships between variables and predict outcomes rather than specifically segmenting customers. Participant observation involves observing behavior in a natural setting to gather qualitative data, which can inform about customer behavior but is not a direct means for segmentation. Therefore, perceptual mapping is the most suitable technique for understanding and differentiating customer segments based on their perceptions and attitudes toward products or brands.