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Information Systems Continuance


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Review of Limayem, M., S. G. Hirt, and C. M. K. Cheung (2007), “How Habits Limits the Predictive Power of Intention: The Case of Information Systems Continuance,” MIS Quarterly, Vol. 31, No. 4, 705-737.

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Information Systems Continuance

  1. 1. 3 JUNE 2011 LITERATURE REVIEW On QUANTITATIVE RESEARCH METHODSLimayem, M., S. G. Hirt, and C. M. K. Cheung (2007), “How Habits Limits the Predictive Power of Intention: The Case of Information Systems Continuance,” MIS Quarterly, Vol. 31, No. 4, 705-737. Prepared by Michael LingPrepared by Michael Ling Page 1
  2. 2. 3 JUNE 2011INTRODUCTION Past research in continued usage of IS was limited to the study of initial ISadoption, which was under the assumption that it was primarily driven by intention.The authors recognized that this assumption had ignored the effect of frequentlyperformed behaviours on IS continuance. This paper contributed to IS research by exploring the roles that IS Habit tookin the context of continued IS usage. It proposed that IS Habit had a moderatingeffect on IS Continuance Intention to the extent that its effect on IS ContinuanceUsage would diminish as the usage behaviour became more habitual. Drawing from the habit literature, the IS Habit construct and its fourantecedents were developed: frequency of prior behaviour, satisfaction, stablecontext and comprehensiveness of usage. PLS was employed as the researchmethod where three competing models were compared for the effect of IS habit on ISContinuance Usage. The moderator model was found to possess the bestexplanatory power.Prepared by Michael Ling Page 2
  3. 3. 3 JUNE 2011SUMMARY Data collection was divided into three rounds over a 4-week period to measureuniversity students’ usage of WWW. A total of 553 respondents answered the firstquestionnaire, and 227 respondents participated in all three rounds. The first roundwas to collect data for Perceived Usefulness, Confirmation, Satisfaction and ISContinuance Intention; the second and third rounds were to measure IS ContinuanceUsage. In particular, IS Continuance usage was measured by two items – frequencyof WWW usage (how often?) and intensity of usage (how many hours?). The authors developed a six-item IS Habit scale. However, only the bestthree items, which had composite reliability of 0.88, were used. The data were analysed using PLS-Graph, which was selected for thefollowing reasons: (i) the formative nature of some of the measures and the non-normality of the data; (ii) it was better suited to test moderation effects; (iii) it allowedfor small to medium-sized samples. Regarding convergent validity, all reflective items had significant path loadingsat the 0.01 level, and acceptable levels of composite reliability (at 0.773 or above)and average variance extracted (at 0.630 or above). The two formative items of ISContinuance Usage had weights of 0.67 (t = 7.6) and 0.500 (t = 4.924). Regarding discriminant validity, each construct shared greater variance withits own block of measures than with other constructs that represented a differentblock. The reflective measures fulfilled the criteria of cross-loadings. A relatively large correlation (r = 0.751) was found between IS ContinuanceIntention and IS Habit, which suggested that the measurements might have drawnfrom the same construct. Nevertheless, the authors defended this point onPrepared by Michael Ling Page 3
  4. 4. 3 JUNE 2011theoretical grounds and by citing similar empirical results from Towler and Shepherd(1991-1992) and Trafimow (2000). Regarding common method bias, LISREL were conducted on six indicators(three from each of the IS Continuance Intention and IS Habit measures) and twolatent variables (IS Habit and IS Continuance Intention) and a method factor. Thefindings showed the fit of the model did not improve significantly. Regarding non-response bias, the demographics of respondents in the firstround, but not in the last, were compared to those who participated in all threerounds. No significant differences were found. Three models were tested to determine which one provided the bestexplanatory power for IS Continuance Usage. A baseline model withoutincorporating the IS habit construct (R2 = 0.180), a second model that modelled IShabit as having a direct effect (R2 = 0.211) and a third model that modelled habit as amoderator (R2 = 0.261). All path coefficients were reported significant at the 0.01level. The hierarchical difference test showed that the interactions effect had aneffect size f of 0.063 which, according to the authors, represented a medium effect.Prepared by Michael Ling Page 4
  5. 5. 3 JUNE 2011CRITIQUE SEM was appropriate in this research as it allowed the specifications of therelationships among the constructs and the measures underlying the constructsconcurrently, so that the measures of the construct and the hypothesized modelcould be analysed simultaneously. The selection of PLS-Graph, a component-based partial least squaresmethodology, was appropriate compared to other covariance-based SEM (such asLISREL) because PLS-Graph was better for theory development and predictiveapplications. The authors developed the antecedents of IS Habit: satisfaction, frequency ofpast behavior, comprehensiveness of usage and stability of context. However,stability of context was not used since “data are collected in only one context and wetherefore control for its impacts.” Nevertheless, the authors characterized stability ofcontext as “the presence of similar situational cues and goals across more or lessregularly occurring situations.” It was arguable that variations existed in universities,just like any other social institutions, such as availability of facilities and examinationperiods were likely to influence students’ usage of the WWW. As the research wasconducted over a period of four weeks, the probability that the respondentsexperienced such unstable events could not be overlooked. The inclusion of thestability construct might have increased the explanatory power of the model. The authors defended the high correlation (r = 0.751) between IS UsageIntention and IS Habit by citing references from theory and by making reference tosimilar high correlation results previously found. Nevertheless, the high correlationwas a concern. The IS Habit measure was a new scale which, for all intents andPrepared by Michael Ling Page 5
  6. 6. 3 JUNE 2011purposes, would be different from other habit measures previously used. Thus, itwas not convincing to support their correlation results with previous habit scales.The authors could have run the model unconstrained and also constraining thecorrelation between constructs to 1.0. If the two models differed significantly on achi-square difference test, then the two constructs would be different. Common method variance was a type of spurious internal consistency whichoccurred when the apparent correlations among indicators were due to a commonsource. Since the data was based on self-reports, the correlation might be due to thepropensity of the subjects to answer similarly to multiple items even when there wasno true correlation of constructs. LISREL test concluded that common methodvariance was not an issue. Convergent validity could be assessed in several ways: (i) the correlationsamong items which made up the scale – internal consistency validity; (ii) thecorrelations of the given scale with measures of the same construct using scalesproposed by other researchers and, preferably, already accepted in the field –criterion validity; (iii) the correlations of relationships involving the given scale acrosssamples or across methods. The results of Cronbach’s alpha and the averagevariance explained (AVE) provided evidence for internal consistency constructvalidity. The authors demonstrated criterion validity for Perceived Usefulness,Confirmation, Satisfaction and IS Continuance Intention by referring to scales thathad been validated in prior research. The authors developed a six-item habit scaleand used the best three items in this research but fell short of providing detail for thedecision. It would be helpful if the new habit scale were to be compared againstPrepared by Michael Ling Page 6
  7. 7. 3 JUNE 2011previously developed habit scales. All the constructs were not tested for convergentvalidity using cross samples or methods. Discriminant validity referred to testing statistically whether two constructswere different. Evidence was provided for discriminant validity, as below: (i) the itemloadings were higher for their corresponding constructs than for others; (ii) the squareroot of the AVE for a given construct was greater than the correlations between it andall other constructs. The authors did not provide any reference to content or face validity. It was aconcern that whether the items measure the full domain implied by their label. Theindicators might exhibit construct validity, yet the label attached to the concept mightbe inappropriate. Use of surveys or panels of content experts or focus groups weremethods in which content validity might be established. Internal validity had not been adequately addressed by the authors. Thenumber of respondents participated in the three rounds was different – 553 in the firstround and 227 in all three rounds. It was not clear what sample size was used in themodel testing. The authors did not address the issue of mortality bias, which was anobviously important issue here. For example, was there an attrition bias? Another internal validity issue that had not been addressed was compensatoryrivalry. As the data collection took three weeks, the students might have promotedcompetitive attitudes that could have biased the results. The latent constructs that were associated with reflective measurement itemswere Confirmation, Habit, IS Continuance Intention, Perceived Usefulness andSatisfaction. The loadings of the reflective items were reported significant.Prepared by Michael Ling Page 7
  8. 8. 3 JUNE 2011Overall Assessment The choice of PLS-Graph was appropriate. The derivation of a new scale forIS Habit was a significant contribution to IS research. The authors obtained thehighest R2 in the IS Habit moderated model against the baseline and the direct effectmodels. Though the R2 value (0.261) of the moderating model was low, theconclusion that the moderating model had the best explanatory power was correct.The exclusion of the stability context antecedents in the IS Habit construct mighthave reduced the variance explained by the model. The high correlation between ISUsage Intention and IS Habit was a potential concern. Convergent validity,discriminant validity and common method bias were largely in order. Content validityand internal validity were not adequately addressed. On balance, there were morestrengths than weaknesses in the paper.Prepared by Michael Ling Page 8
  9. 9. 3 JUNE 2011CONCLUSION The key contribution of the paper rested on the scale development of the ISHabit construct and the finding that there was moderating effect of IS Habit on ISContinuance Intention and IS Continuance Usage. The choice of the component-based PLS model, PLS-Graph, was appropriatefor the analysis. Three competing models were compared and the moderating modelwas found to have the highest explanatory power. All loadings and weights of theindicators were acceptable. The research could have improved by addressing the concerns raised here.In particular, further developed measurement scale of IS Habit; the inclusion ofstability in the model; consideration of interactions effect between Satisfaction andComprehensiveness of Usage and Frequency of Behavior.Prepared by Michael Ling Page 9