From the turn of the century, there was a great deal of interest in how advertising worked. Until Krugman's research, a "hierarchy of effects" model of advertising was commonly accepted. According to this model, a consumer moved toward a purchase decision in a rational manner. First, a consumer became aware of a brand, then formed an opinion, and finally they made the decision to buy the product. The AIDA model developed in the 1920's suggested that effective marketing communication should attract attention, gain interest, create a desire and lead to action.

Numerous models of this sort were proposed. Another was AIETA (awareness - interest - evaluation - trial - adoption). Hierarchy models shared the belief that consumers acted in a rational manner, and that attitudes preceded behavior (Krugman, 1977). Within such a model the role of advertising was clear. Its task was to create or reinforce attitudes, which in turn would lead to purchasing.

However, Krugman and others found that this did not always hold true. Advertising researchers found that even after intensive advertising there was little change in attitude, and even recall was weak. It seems logical that there must be an alternative model to explain advertising effectiveness, when no change in attitude or recall is evident. Yet, when first presented, Krugman's ideas were shocking. Could people learn without reasoning?

In light of the time is is understandable. During World War II and in years following, there was a great deal of interest in mass communication and its power to persuade. Books like Vance Packard's The Hidden Persuaders written in 1956 cast advertisers as manipulators of the public. Far removed from that period, it is now easier to consider the merits of Krugman's theory without alarm. Low-involvement theory can be taken with a grain of salt. It is applicable in some cases and not others. Let's take a look at what Krugman suggested.

The above model (Ray, 1973) summarizes Krugman's notion of low-involvement theory. First, Krugman states that watching television is a passive activity. Television viewers are not engaged with the message, therefore their defense is low. After repetition of the advertising message there is a gradual shift in cognitive structure. He believes that this cognitive shift does not appear as attitude change until there is a behavior, such as a purchase. Only after trial is there change in attitude.

The above model simplifies the concept a little. Krugman's research dealt specifically with television but the concept could be applied to radio or outdoor as well: media in which there often is little opportunity to consider detailed information. After repeated exposure to an ad, the image of the brand is absorbed into memory. While there may be no recall of the brand, the consumer recognizes the brand at the point of purchase. The product is of no great importance to the consumer, so it is not unreasonable to think that little thought goes into the purchase decision. After trying the product, an attitude is formed about the brand.

Michael L. Ray, following Krugman's lead, argued that different hierarchies were appropiate to different situations. The implication of Ray's research was that traditional "hierarchical" learning occurred under high-involvement conditions, while the "awareness - behavior - attitude" hierarchy occurred under low-involvement conditions. The key determinate between such situations was the level of involvement, or interest, in a product category. The above model describes the low-involvement and low product differentiation hierarchical sequence (Harris, 1987). Ray's research confirmed that repetition of messages increased recall and purchase intention but had little effect on attitude (Kassarjian & Kassarjian, 1979)

Now, let's take a look at some of the implications of low-involvement theory for advertisers.