TAM and the Economic Man

The Technology Acceptance Model

First proposed by Fred Davis in 1989, TAM is one of the most mature modules dealing directly with Human-Comupter interaction. It theorized that system usage is a response that can be predicted or measured by user motivation, which is influenced by the system’s capabilities and features.

Later, the theory evolved to a predictive model that measured the likelihood of usage as a calculation of perceived ease of use and perceived usefulness. Davis formalized these terms as: Perceived ease of use: The degree to which an individual believes that using a particular system would be free of physical and mental effort. Perceived usefulness: The degree to which an individual believes that using a particular system would enhance his or her job performance.

Essentially, the Technology Acceptance Model is a model for describing the likeliness of an innovation’s usage by a user based on self-perceived notions of usefulness and ease of use. It is interesting for so much value to be placed on a user’s perception of a system rather than actual experience.

We are very concerned with user expectations when designing interfaces for good reasons, as Donald A. Norman discusses at length in his book the Design of Everyday Things.

Expectations of Ubiquitous Tech

The increasing ubiquity of technology has greatly changed the implications of TAM, which was originally developed at a time where technology was only available at the workplace. Today, the role of technology has expanded to every aspect of our daily lives. In effect, the decision for adopting a technology is an increasingly prominent event affecting every aspect of our lives.

Unfortunately, the validity of TAM has historically relied on self-assessment methods in studies with users. These methods rely on the assumption that a person can accurately assess and report his/her emotional experiences. While self-reports offer insights into the subjective user experience, they do not explain the rationale behind user behaviors.₁

Therefore, models that help explain the human decision making process should be examined for usage in conjunction with TAM.

Homo economicus

In economic theory, human behavior is similarly modeled on one’s own perception and their actual actions though the model of Homo economicus, or the Economic Man. The Economic Man model depicts human actions as the result of choosing the best option based on the fulfillment of his or her “utility function”, meaning the ability to maximize any situation that involves choice.

Adam Smith’s Wealth of Nations introduced the idea of the Invisible Hand, a subconscious force in free markets to adjust prices through the collective self-interested actions of all individuals. Smith proposed that the economic man is driven by a relentless desire to improve his condition; a common self-seeking trait of humanity. ₂ This model of humanity proved instrumental in relating economic behavior to individual psychology and shaped the course for modern economic theory.

Expanding our Models

The underlying human factors of HCI has allowed for widespread multidisciplinary integrations within the field. The commonality between the two models and their focus on subconscious human motivations for predicting actual behavior is representative of the basis of human nature. Ease of use and usefulness are directly applicable to the economic human variable of utility. If a user does not think an innovation will add to their utility, then they will not adopt its usage into their processes.

By combining the similarities of TAM and the Economic Man, we can further explore the user’s rationale behind their decision to use a particular innovation, which could lead to a more comprehensive understanding of user behavior.