At the top of the black box the model lists a number of external variables that can significantly influence buyer decisions. These variables are not well defined as other aspects of the model because they are external to the buyer.
Although there are various aspects of the model; that are beyond the scope of this article a brief review of its operation is appropriate. The process starts when a buyer confronts an input stimulus and it achieves attention. The stimulus is subjected to perceptual bias as a result of the influence of the buyer’s predispositions as affected by his or her motives, decision making, decision mediators and evoked set. The modified information will also influence these variables which in turn, will influence his or her predisposition to purchase.
The actual purchase is influenced by the buyer’s intentions and inhibitors which are confronted. A purchase leads the buyer to evaluate his or her satisfaction with it, and satisfaction increases the buyer’s predisposition towards the brand. As the buyer acquires more information about brands he or she engages in less external search for information and exhibits more routine purchase behavior.
The Howard Sheth model represents significant contribution to understanding consumer behavior. It identifies many of the variables influencing consumers and details on how they interact with each other. Also, the model and the earlier work on which it is based recognizes explicitly for the first time different types of consumer problem solving and information search behaviors. It also recognizes that outcomes of consumer decisions that are more than just purchaser.
Of courses the model has certain limitations. First, it does not make sharp distinctions between exogenous and other variables. Second, some of the variables are not well defined and are difficult to measure. The model also has limited generality. For example it is not highly useful in explaining joint decision making between family members or other members of an organization. Finally the model is quite complex, making it difficult to comprehend especially for those new to the field.
Engel Blackwell Miniard Model:
The Engel Blackwell Miniard model was originally developed in 1968 by Engel Kollat and Blackwell and has gone through numerous revisions. Most recently the model has been contributed to by Miniard in conjunction with Engel and Blackwell. It stands as one of the most popular representations of consumer behavior.
The scheme shown depicts consumer behavior as a decision process of five activities which occur over time: (1) motivation and need recognition (2) search for information, (3) alternative (4) purchase and (5) outcomes. As shown in the model, variables are grouped into four general categories (a) stimulus inputs (b) information processing (c) decision process and (d) variables influencing the decision process. Arrows in the model depict major directions of influence that specific variables exert. The following discussion of the decision process characterizes the role and nature of these variables.
Similar to the Howard Sheth model, the authors recognize two significantly different modes of operation by consumers. One is described as an extended problem solving behavior (EPS) which is characterized by high levels of involvement and/ or high levels of perceived risk. Under EPS the product evaluation process will be rigorous and if necessary the consumer will shop at many outlets. In addition satisfaction with the brand is crucial for continued commitment to use the brand. In limited problem solving behavior (LPS) the consumer is operating under low levels of involvement and /or low levels of perceived risk. Consequently he was low on motivation to search for brand information and was only wiling to engage in a non-rigorous evaluation of alternatives. He is not motivated to shop at many outlets and satisfaction with the purchase will encourage repurchase because of inertia not real loyalty with the product .
The authors argue that the same basic model can be used to characterize both EPS and LPS behavior. What will change is the degree to which various sages in the model will be used by consumers. Looking at extended problems solving behavior first the model is activated with the consumer recognizing a need from three possible influences – Information stored in memory, environmental influences, and individuals characteristics such as involvement level of consumer. Typically the consumer becomes aware of a disparity between his present state and his concept of the ideal state of affairs – the state where he would really like to be. Because involvement is high, EPS is usually activated by exciting those motives that are closely related to the consumer’s self concept.
Source: Consumer Behavior