A decision tree serves as a map for shelf layout. It is a rationalized model of a number of hierarchical stages the shopper unconsciously undergoes to find the product for purchase. Finding the optimal decision tree means understanding the relative importance of all elements in the decision process.
In this test, different simplified shelf layouts (with a variation in products, placement, prices, etc.) are randomly presented to participants that reflect actual market volumes. For each shelf layout, the participant indicates which product he would purchase.