Information Integration Theory

Information Integration Theory (IIT) was developed by Norman H. Anderson, a cognitive psychologist, in 1981. The theory is mainly used in the fields of marketing, communication, and psychology, but also includes subfields such as personal cognition, cognitive development, decision theory, and language processing. The theory explains how attitudes are formed and changed through the integration of new information with existing knowledge, thoughts, and cognitions. Anderson (1981) explores the fact that when people perceive new information, it does not replace our existing views. This theory assesses the psychological processes that are unobservable but occur when an individual integrates information from two or more stimuli and constructs a quantitative value.

In this theory, a message is considered as fragments of information that have two relevant characteristics: value and weight. The value of an information fragment is its evaluation (favorable or unfavorable), and the weight explains the perceived importance of the information. Both factors influence our opinions and state of mind. Thus, information with a high value and weight will have more influence on our attitudes than unwanted and unimportant messages. The theory of information integration points out that with new positive information, negative attitudes tend to become less negative and positive attitudes become even more positive.

The information integration process has three unobservable stages:

  • Evaluation: this is the interpretation of the stimuli. This is the phase where the individual evaluates the important information of a stimulus psychologically.
  • Integration: this is the psychological integration of the elements of the new information. This is the phase where the individual internalizes the new information to reach a final conclusion.
  • Response construction: this is the continuation of the first two stages (evaluation and integration). This is the phase where the individual converts the internal impressions into an obvious and observable response.

In summary, IIT is a process that aims to extract quantitative values and ultimately result in a quantifiable response after a psychological process.

Furthermore, Norman (2012) presents a model for integrating information from consumer evaluations and intentions. Using ITT, the author is able to describe the process the consumer goes through when considering multiple brands in the same context. His results showed that the effect of information on personal evaluations is based on the two characteristics of this information: value and weight. Therefore, the positively perceived information fragment could have a strong or weak/no impact depending on the weight given to the information. Furthermore, Norman provides with this article a clearer application of Anderson's (1981) theory of information integration.


Anderson, N. H. (1981). Foundations of information integration theory. New York: Academic Press.

Norman, A. T. (2012). Branded products in service encounters: an information integration model of consumer evaluations and intentions. Services Marketing Quarterly, 33(3), 230-245.