EXAMPLE 15.6 Two-Way Design for the Shelf Display Study

We use a design for our shelf display study. The two factors are shelf display organization and product quantity. For product quantity, we compare the levels low (or scarce), medium, and high. The study that this example is based on used a convenience sample of undergraduate students taking a marketing class. Although aware of the potential hazards with this type of sampling, we obtain 72 student volunteers from our university. Each student is randomly shown one of six pictures of the shelf display. We measure purchase intent through a series of questions that are scored on a 1 to 7 scale.