Much of family decision making centers on consumer behavior (Melson, 1980). However, the researchers in the disciplines of marketing and family sociology, who traditionally studied consumer decision making and family decision making, respectively, have not, to date, awarded the family consumer decision making process the attention it would seem to warrant. Thus, the objective of this research was to model the process that a family as a group goes through, while making a consumer decision. Both the intricacies of the variation in interaction that occurs between family members at different stages of the consumer decision and the effect of the immediate environment on these interactions were given special attention. In summary, the domain of the model is restricted to the study of the family as a multiperson buying unit as it goes through the seven stages of a high involvement, consumer decision. The model is comprised of three major components and is pictorially represented in a nested cup scheme so as to illustrate the systems approach to conceptualizing the study of the family. The outer circle represents the external environment and is comprised of several sets of variables. Within this model, the external environment is viewed as affecting the decision process and family member involvement, with recognition that this latter influence is filtered through the internal environment (family system). The second circle depicts the family as a system and is referred to as the internal environment. It contains numerous sets of variables, several of which contain sub-concepts as well. These internal variables are viewed as individually or collectively having direct influence on the core of the model. The inner core of the model is divided, with the left side depicting the seven stages of the decision process while the right side illustrates family member involvement at each stage. The stages of the decision process are a combination of the decision process component of the EKB model (Engel and Blackwell, 1982) and the concept of the problem solving loop from the Kieren, Vaines and Badir (1982) model. The core of the model is seen to be affected by the external and internal environments as well as by other variables within the core. Definitions of the variables (approximately 120) are grouped according to the three components of the model. Propositions (approximately 250) are ordered into ten sets which in turn are organized according to external, family and process/product categories. A summary matrix supplements the extensive listing of propositions and provides a means of viewing all of the propositions simultaneously. An expert review panel was established and a response sheet was developed, both for the purpose of reviewing and evaluating the model. Panel responses were discussed and the panel's recommendations were either incorporated into the current version of the model in Chapter II or are included in the final chapter as recommendations for future revisions and refinements of the model.