Validity of other measures in the extended TAM
Additional analyses were performed to assess the validity of other ETAM measures. Using
principal component analysis, the four items that measured perceived usefulness of the
systemloaded on a single factor accounting for 83 percent of the variability. Factor loadings
for the four items range from 0.90 to 0.92, indicating convergence and a strong relationship
between the items and the underlying construct as well. Thus, we averaged participants’
responses to the four items to form the measure of perceived usefulness (PU).
Similarly, the four items that measured perceived ease of use of the system loaded on
a single factor accounting for 82 percent of the variability. Factor loadings range from
0.84 to 0.93. Participants’ responses to the four items were averaged to form the measure
of perceived ease of use (PEU).