||Availability designs allow the estimation of cross effects models. Cross effects models provide a way of testing whether IIA obtains in choice data. They also may be used to model the competitive structure of markets. Despite their potential value, cross effects models are not widely used in choice-based conjoint measurement. However, it has recently been established that they may be estimated with fewer choice sets than previously thought necessary. Use of the models may significantly increase because of this finding. The present paper briefly illustrates how an availability design and corresponding estimation matrix X is generated. It also shows how full-information estimation and hypothesis testing may be conducted.