社會媒體管理課程 -Paper Reading

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FRED D. DAVIS, RICHARD P. BAGOZZI AND PAUL R. WARSHAW

Management Science. Vol. 35, No, 8, pp.982-1003, 1989.

USER ACCEPTANCE OF COMPUTER TECHNOLOGY:

A COMPARISON OF TWO THEORETICAL MODELS

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

• Introduction• Theory of Reasoned Action (TRA)• Technology Acceptance Model (TAM)• Comparison• Research Questions

Outline

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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)

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• 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“.

TRA (cont.)

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• 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

TRA (cont.)

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• 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

TRA (cont.)

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• 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

Technology Acceptance Model(1986)

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• 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.

TAM (cont.)

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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.

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