The Influence of External Variables on Information Technology Usage Behavior

The Technology Acceptance Model (TAM) predicts the user acceptance of end-user applications by specifying causal relationships among external variables, belief and attitudinal constructs, and actual usage behavior. Although the perceived usefulness and perceived ease of use constructs have received much recent attention in the MIS literature, few studies have attempted to validate the fill TAM model with all of the original constructs. Furthermore, the many published TAM studies are characterized by the use of different measurement factors to assess the belief constructs. This study validates TAM using the original constructs and assesses the effects of TAM variables on two measures of usage behavior. Results are largely consistent with previous TAM studies. However, the impact of external variables is not fully mediated by the TAM constructs. and refines previous related research by addressing these points. The specific objectives of this study are: (1) to validate TAM using the original belief and attitudind constructs; and (2) to examine the direct and indirect influences of select external variables on usage behavior. 2: Theory and background Fishbein and Ajzen’s [19] [20] Theory of Reasoned Action (TRA) and Davis’ [8] [9] [lo] Technology Acceptance Model (TAM) provide theoretical contexts for measuring beliefs in order to predict future behaviors. TAM is an adaptation of TRA that is specific for modeling user acceptance of information systems. TAM suggests that two particular beliefs, perceived usefulness and perceived ease of use, are of central relevance for predicting computer user acceptance behaviors. Figure 1 illustrates the TAM model [lo].