Basic Concepts Underlying the PARAFAC-CANDECOMP Three-Way Factor Analysis Model and its Application to Longitudinal Data

This introductory article was written to explain the ideas behind PARAFAC-CANDECOMP three-way factor analysis, including the idea of three-way data, the three-way factor analytic model, the uniqueness of axes obtained and the significance of this uniqueness. Also included is a discussion of the computational characteristics of the PARAFAC-CANDECOMP algorithm, touching on the simultaneous extraction of factors, and how to check one's solution for convergence, optimality, and uniqueness.