Developed in 1965, the Andreasen model was developed from recognition of the importance of information in the consumer decision making process. The model also emphasises the importance of consumer attitudes despite the fact that it did not take the importance of attitude into consideration with regards to repeat purchases. 

The model was developed from several ideas about attitude formation and change drawn from social psychology. The entire process from stimulus to outcome comprises an information–processing cycle which involves four stages: input stimuli, perception and filtration, disposition changes and various feasible outcomes.

Thus information about the product would be transmitted to the consumer through the five senses. It is possible for these messages to either be personal or impersonal. A filter will be formed with the consumer’s perception, while attitudes will function as a determining factor that will let information flow through. There are however different ways in which attitudes can be changed. Thus changing group affiliations would most likely lead to a consumer conforming to the new group norms.

The model takes cognisance of the fact that new information can have an effect on the consumer’s attitudes, beliefs and feelings. Consumer decisions are further affected by cultural values, personality experience and wants. It also takes cognisance of the environmental factors that affect consumers’ decision making processes.

In spite of these, the model has limitations which include the fact that the model does not give a clear indication of the interaction that exists between the consumer and the firm. There seem to be a one-way communication in the model. The decision making process explained only deals with new products. Furthermore, the model appears to give attitudes a lot of weight at the expense of other variables, which could have been included or developed further. The relationship between many of the variables is not properly specified. Finally, the model does not take special situations into account.