To ensure content validity, items selected for the constructs,
shown in Appendix, were primarily revised from prior studies for
the context of on-line shopping. All the constructs, except for the
demographic variables of the subjects, were measured on a fivepoint
Likert-type scale. (Table 1) summarizes the operational definition,
variable type, source of measurement items, and number of
items of the three constructs in this study, including past on-line
shopping experience, perceived information overload, and subjective
state towards buying decision.
On-line shopping experience was measured by the subjects'
shopping frequency in e-store (form "never" to "more than 1 O
times"). Some studies tried to incorporate the concept of "perception"
to study information overload phenomena (Buchanan et al.,
2000; Grise and Gallupe, 2000). Their definitions and measurements,
however, are not suitable for consumer buying context.