Introduction to Information Systems Models and Methodologies - High Level Models and Methodologies for Information Systems - page 14

Fig. 1.5 Technology acceptance model (adapted from Davis 1986 )

was to provide a description of the speci c mechanisms by which perceived use-

fulness is formed, considering that it was the most fundamental factor in the original
TAM model.
Essentially, all quality evaluation models have attempted to bring together the
key aspects that form or influence user ' s cognitive processes and behavioral
decisions. Venkatesh et al. ( 2003 ) combined eight existing models found in pre-
vious literature to create what they described as the uni ed theory of acceptance and

use of technology (UTAUT). They started by outlining a list of constructs used in
the existing models and pinpointed which constructs appeared to more useful and
signi

cant in empirical research. From there, they determined that the more
important factors of user acceptance could be summarized in four variables: per-
formance expectancy, effort expectancy, social in uence, and facilitating condi-

tions. External factors, such as gender, age, experience, and voluntariness of use,
acted as moderating elements over those variables. The differing levels of impact
resulted in particular behavioral intentions, and use behaviors.
These and other models of technology and IS acceptance have in common the
importance of individual perceptions, although different theories consider different
factors to be of in

uence in shaping those perceptions. These models are particu-
larly useful for developers and designers, allowing them to adjust the models to the
project, and determine what factors will most likely determine the user ' s acceptance

of the final released product.

1.8 IS Models for Success Assessment

As we have seen, the concept of IS success has been closely interrelated with the
concept of user acceptance, in accordance with behavioral theories. The pioneering
work of DeLone and McLean ( 1992 ) established the basics for the creation of a
model of IS success assessment, centered on the premise that use of the system is
intimately related with user satisfaction. It attempted to describe the acceptance of a
system through a causal explanatory approach, where use and user satisfaction,

constantly feeding on each other, directly in

-

uence individual impact, which

eventually re ects on organizational impact (Iivari 2002 ). This model was later