社會媒體管理課程-Paper Reading
USER ACCEPTANCE OF
COMPUTER TECHNOLOGY:
A COMPARISON OF TWO
THEORETICAL MODELS
FRED D. DAVIS, RICHARD P. BAGOZZI AND PAUL R.
WARSHAW
Management Science. Vol. 35, No, 8, pp.982-1003, 1989.
指導教授：戴敏育 老師
報告者：蕭詩寰 . 杜 駿
學號：700630113 .
日期：2011/10/06
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Outline
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Introduction
Theory of Reasoned Action (TRA)
Technology Acceptance Model (TAM)
Comparison
Research Questions
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Introduction
• Theories Used in IS Research: Technology acceptance model
• History:
1975 ,Fishbein, M., and Ajzen, I(1975). “Belief, attitude, intention and
behavior: an introduction totheory and research,” Addison-Wesley,
Reading MA., 1975.
1986 , Davis, F. D. (1986). A technology acceptance model for empirically
testing new end-user information systems: Theory and results.
Doctoral dissertation.
1989, Davis, F. D. (1989). Perceived usefulness, perceived ease of use,
and user acceptance of information technology. MIS Quarterly, 13(3),
319-339.
1989, Davis, F. D., Bagozzi, R. P., & Warshaw, P. R. (1989). User acceptance
of computer technology: A comparison of two theoretical models.
Management Science, 35(8), 982-1003.
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Introduction (cont.)
• Why do we care about technology acceptance?
• Users’ internal belief and attitudes on usage behavior
-these research findings have been mixed and inconclusive
• intention models from social psychology as a potential
theoretical foundation for research on the determinants of
user behavior  Theory of reasoned action( TRA)
• To explain and predict user acceptance and rejection of
computer-based technology
• How to measure?
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Theory of Reasoned Action(1975)
• Behavioral Intention (BI) is a measure of the strength of one's
intention to perform a specified behavior.
• Attitude(A) is defined as an individual's positive or negative
feelings about performing the target behavior.
• Subjective norm(SN) refers to “ the person 's perception that
most people who are important to him think he should or
should not perform the behavior in question“.
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TRA (cont.)
• A person 's attitude(A) toward a behavior is determined by his
or her salient beliefs (bi ) about consequences of performing
the behavior multiplied by the evaluation (ei) of those
consequence.
• 態度=執行此行為的後果之信念*執行此行為的後果之評估
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TRA (cont.)
• An individual's subjective norm (SN) is determined by a
multiplicative function of his or her normative beliefs (nbi ) ,
and his or her motivation to comply (mci) with these
expectations.
• 主觀規範=規範信念*服從動機
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TRA (cont.)
• Researchers using TRA must first identify the beliefs that are
salient for subjects regarding the behavior under investigation
• it asserts that any other factors that influence behavior do so
only indirectly by influencing A, SN, or their relative weights.
 external variables
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Technology Acceptance Model(1986)
• The goal of TAM is to provide an explanation of the
determinants of computer acceptance that is general, capable
of explaining user behavior across a broad range of end-user
computing technologies and user populations, while at the
same time being both parsimonious and theoretically justified.
• A key purpose of TAM therefore, is to provide a basis for tracing
the impact of external factors on internal beliefs, attitudes, and
intentions.
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TAM (cont.)
Two particular beliefs:
• Perceived usefulness(U) is defined as the prospective user's
subjective probability that using a specific application system
will increase his or her job performance within an
organizational context.
• Perceived ease of use(EOU) refers to the degree to which the
prospective user expects the target system to be free of effort.
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Comparison
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Research Questions
1. How well do intentions predict usage?
2. How well do TRA and TAM explain
intentions to use a system?
3. Do attitudes mediate the effect of beliefs on
intentions?
4. Is there some alternative theoretical
formulation that better accounts for
observed data?
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Empirical Study
• Who and What
• Salient Belief Elicitation
• How
– Belief
– EOU and U
– Usage
Who and What
• 107 full-time MBA students during their first
of four semesters in the MBA program at the
University of Michigan
• WriteOne
– Voluntarily used package,unlike
spreadsheet,statistical programs
– Face opportunities to use a word processor
throught out the MBA program for multi-purpose
– Most frequently used
Salient Belief Elicitation
• Telephone interview 40 MBA students who
were about to enter their second year of the
MBA program
• Reason:
– Just completed a year of study
– Not practical to ask first-year students their beliefs
prior to this initial indoctrination
– Omitting a salient belief are considered more
severe than those of including a nonsalient one
HOW-Belief
• Interviewees were asked to list separately the
advantages,disadvantages,and anything else
they associate with becoming a user of
WriteOne.
• The seven frequently mentioned outcomes
were chosen.
HOW-EOU and U
• Generating 14 candidate items for each
counstruct based on their definitions
• Pre-testing the tiems to refine wording and to
pare the items set dowm to 10 items per
construct
• Assessing the reliability and validity
• from 10 to 6 to 4 items
• Measure with 7-point scales
HOW-usage
• Using 2 questions regarding the frequency
with which the respondent currently uses
WriteOne
• 7-point scale
• Checkbox list format
• Self-reported frequency measures should not
be regraded as precise measures of actual
usage frequency
Conclusion
• People’s computer use can be predicted
reasonably well from their intentions
• Perceived usefulness is a major determinant
of people’s intentions to use computers.
• Perceived ease of use is a significant
secondary determinant of people’s intentions
Conclusion
• Intentions measure after a one-hour introduction
– To evaluate system early, caonnot obtain user
experience with prototypes to assess user reactions to
systems used on a trial basis in advance of purchase
decision.
– Given the limited experience with the system,
intentions would not be expected to be well-formed
and stable.
Conclusion U-EOU
• At brief time, EOU had a significant effect on BI,
while at over time, users learned to effectively
operate the word processor, the direct effect of EOU
on BI disappeared.
• As learning progressed over time, EOU became less
salient.
• Reflecting considerations of how the relative effort of
using the system would affect the overall
performance impact the system offered.
Conclusion U-EOU
• EOU would have been for managers and
professionals more generally.
• With more complex or difficult systems, ease
of use may have had a greater impact on
intentions (Because WriteOne is still only one
system)
Conclusion SN-BI
• Compare to other measures for TRA,SN scale
is particularly weak from a psychometric
standpoint.
• Word processing is fairly personal and
individual,and may be driven less my social
influnces
Conclusion A-BI
• Attitudes intervened between beliefs and
intentions far less than hypothesized by either
TRA or TAM
• Attitude construct did little to help elucidate
the causal linkages between beliefs and
intentions in the present study
• only partially mediate these relationship
Conclusion
• Although ease of use is clearly important, the
usefulness of the system is even more important.
• Users may be willing to tolerate a difficult interface in
order to access functionality that is very important,
while no amount of EOU will be able to compensate
for a system that doesn’t do a useful task