Developed in 1969, the Howard-Sheth model is a descriptive model constructed by John Howard and later refined by Jagdish Sheth. There are four sections to the model. These are inputs, perceptual constructs, learning constructs and output. Business and environmental factors such as family, reference groups and social class are explained in the input section.

Thus stimulus ambiguity will occur when the stimulus makes contact with the consumer’s senses. This will lead to a search for more information which will be sorted by continual bias gained from attitudes, confidence, search and motives. It is possible for the new information to lead to changes in motives and intention, which could influence confidence and purchase.

The model sees buying behaviour as comprising of three stages. These are extended problem solving, limited problem solving and routinized response behaviour. Extended problem solving comes from a limited number of fixed criteria, which the consumer uses to evaluate product categories. In limited problem solving, there will be limited information search.

This is due to the fact that the consumer already has basic criteria which will be used when conducting an information search. In routinized problem solving mode, the consumer will evaluate products through the use of established criteria. There will be little or no search for additional information.

The Howard-Sheth model is regarded as contributing significantly to the study of consumer behaviour. Not only does it identify most of the variables that affect the consumer, but it also gives an explanation of the way in which these variables interact with each other. Furthermore, the model is regarded as the first model to recognize and explain the different types of consumer problems solving and information search behaviour. 

The weaknesses of the model lie in the fact that it makes no distinction between high and low involvement decision-making. Neither does it give a clear indication as to whether the needs of the consumer will have any effect on the decision-making process or not. Furthermore there is no differentiation between internal and external information search, as well as the type of situation which would use either.

Thus a consumer could purchase a premium food brand for the first time based on the fact that the brand was one used by their parents. In this situation, there won’t be either extended problem solving, or information search. This situation is characteristic of Howard and Sheth’s routinized behaviour. However, the behaviour is not routinized since the purchase is being made for the first time. Finally, there is discontinuity with some variables. They appear at start of the model but do not continue to the end of the model.