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 full 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. The 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.