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Organisational Citizenship Behaviour: Validating FactorialStructure and Invariance among Employees

Saadia TayyabQuaid-i-Azam University, Islamabad

The major objectives of this investigation were (a) to test for the factorial validity ofthe Organizational Citizenship Behavior Scale (OCBS), for 690 public sectoremployees including permanent (n=508) and contingent (n=182) workers, and (b)to test for equivalence of factorial measurement and conceptual equivalence acrossgroups. Results of exploratory factor analysis revealed that three items are notpsychometrically sound in terms of their target loadings. With a view to furtherimprove the OCBS subsequent confirmatory factor analysis (CFA) resulted indeletion of these three items. A four factor model excluding three problematic itemsprovided the best fit to the data for each group, revealing the homogeneous subscalestructure and equivalence of measurement across two groups. Test of invariancerevealed the equivalency of the remaining items across permanent and contingentemployees indicating that item content was perceived in exactly the same way in

both groups of workers and each group responded to the scale items in a similarconceptual frame of reference. The study has important implications for substantive

research focusing on multi-group comparisons across employer samples.

The study of organizational citizenshipbehavior (OCB) has emerged as an extremelypopular topic of organizational psychology,human resource management, andorganizational behavior. It has been ofincreasing interest to both scholars andmanagers (Lepine, Hanson, Borman, &Motowidlo, 2000; Motowidlo, Borman &

Schmit, 1997; Motowidlo & Schmit, 1999;Organ & Ryan, 1995).

The roots of construct could be tracedback to Barnard (1938) and Katz (1964).Barnad underscored the theoretical andpractical importance of the willingness ofpersons to contribute efforts to thecooperative system (p.83). He described thiswillingness as a posture tending to producevarious constructive gestures. Katz (1964)

distinguished between dependable roleperformance (i.e., in role performance) andwhat he described as spontaneous behavior,ehich includes cooperative gestures, actionsprotective of system, and behavior thatenhances the external image of theorganization. Katz (1964) noted that much ofthe patterned activity that comprisesorganizations goes beyond formal roleprescriptions in the extent to which it isintrinsically cooperative. Furthermore, theincentives (e.g., merit, pay) for excellence ofin role performance do not inhere in formalrole obligations. The presumption is that manyof these contributions aggregated over timeand person, enhance organizationaleffectiveness. Organ (1988) defined OCB asindividual behavior that is discretionary, not

Journal of the Indian Academy of Applied Psychology,

January - July 2005, Vol. 31, No.1-2, 49-64.


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directly or explicitly recognized by the formal

reward system, and that in aggregate promotesthe effective functioning of the organization:(p.4). Organ (1988) suggested that OCB , ineffect, places more resources at the disposalof the organization and obviates the need forcostly formal mechanism to provide functionsotherwise rendered informally by OCB.

The theoretical significance of OCB liesin the observation that it can not be accountedfor by the incentives that sustain in rolebehavior (Organ, 1997). Greater scholarlyinterest in this construct, however, seemed tobe triggered in the early 1980s after Organand his colleagues (Bateman & Organ, 1983;Smith, Organ, & Near, 1983) used the termorganizational citizenship behavior to describeit. The focus of most of early research on OCBwas in response to Organs (1977) interest inthe notion that job satisfaction might influenceorganizational effectiveness behaviorsmanagers want but cannot technically require.

Dimensionality of the OCB Construct

Law, Wong, and Mobley (1998)suggested that scholars have not adequatelydefined OCB with respect to its dimensions.They also described several ways to relatedimensions with the overall construct of OCB.If OV|CB conformed to a latent model, eachdimension would be a manifestation of OCB,and measures of the dimensions would includesome variance reflecting OCB, othersystematic variance not related to OCB, anderror variance. Therefore, OCB would be alatent variable that causes these dimensions.

Motowidlo (2000) suggested that if OCB werea latent construct, it would be similar topersonality construct. That is, OCB would belike a personality trait that causes behaviorsreflected in that dimension. Scholars, however,have not explicitly taken this approach indefining OCB with respect to its dimensions. IfOCB conformed to an aggregate model, itwould be formed as a mathematical functionof the dimensions. According to this

perspective, each of the dimensions would be

part of the OCB construct. OCB would exist tothe extent that systematic variance from eachdimension would be captured and addedtogether law et al. (1998) used the exampleof job satisfaction as an aggregate constructbecause job satisfaction can be thought of asa sum of scores on instrument measuringsatisfaction with pay, co-workers, supervisor,and so forth.

Motowidlo (2000) further pointed out thatcontextual performance is clearly the exampleof an aggregate multidimensional construct.He defined job performance as the aggregatedvalue to organization of behavioral episodesthat have effects on the social, organizational,and psychological context of the organizationstechnical core. Many OCB scholars view thebehavioral dimensions as being related butdistinct. Consistent with this view point, scoreson OCB measures should reflect commonvariance as well as specific variance. Indeedmany OCB researchers have combined scoreson behavioral dimensions into a composite

score (e.g., Allen & Rush, 1998; Chen, Hui, &Sego, 1998). However, the creation of scalecomposites has never been guided by theoryor construct definition. Instead, researcherscreated these composites because theyrecognized that behavioral dimensions of OCBco-vary rather strongly and that combining thescores makes sense with respect to promotingparsimony. Of course, there is a possibility thatOCB is not really a construct at all but insteada set of behaviors that belong together. Thisapproach seems to have been used in

developing early OCB scales. For example,Lepine, Erez, and Johnson (2002) observedthat scholars have introduced many new OCBmeasures without adequate construct validitysupport. They found that there are more thanforty measures of behavior that scholars havereferred as OCB, however, the authors ofthese studies did not empirically evaluate theextent to which these measures were differentor similar to others that already existed. In fact,

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there has been less effort focused on

replicating and conducting studies thatsystematically extend previous empiricalresearch. Indeed, there needs to be anincrease in the amount of effort focused ondeveloping the theory that can guide OCBmeasurement and analysis. Smith et al. (1983)on the basis of structured interviews andsupervisors rating identified two dimensionsof OCB; Altruism, captured behavior directlyintended to help a specific person in a face toface situation, e.g., helping others who havebeen absent, volunteering for things not

required, help co-workers with heavy workloads. The second dimension, generalizedcompliance, represented impersonalbehaviors such as compliance with normsdefining a good worker (e.g., being punctual,above the norm attendance, not spending timein idle conversation).

Although measures of these dimensionscontinue to be used by researchers, somehave modified the response scale. Organ(1988) proposed an expanded taxonomy of

OCB that included altruism,conscientiousness, sportsmanship, courtesy,and civic virtue. Podsakoff, MacKenzie,Moorman, and Fetter (1990) provided the firstoperationalization of these dimensions. Usingthe definitions given by Organ, they generateditems subjected them to a Q sort and CFA.The resulting OCB scales have served as thebasis for OCB measurement in a large numberof studies (e.g., Moorman, 1991; Moorman,Niehoff, & Orhan, 1993; Podsakoff, MacKenzie,& Bommer, 1996). Several other taxonomies

of OCB like behaviors have been proposedand operationalized (e.g., Morrison, 1994; VanDyne, Graham, & Dienesch, 1994). However,the behavioral domains of these taxonomiesoverlap with each other and with organs 1988OCB domain. For example, Van Dyne et al.,s(1994) OCB framework includes socialparticipation, which overlaps withsportsmanship and a bit of civic value; andobedience, which overlaps with civic virtue and

conscientiousness. Morrison (1994) offered

another OCB framework. Her altruismdimension overlaps with Organs (1988)altruism and courtesy dimension. Herconceptualization of conscientiousness is a bitnarrower than organs (Lepine, Erez, &Johnson, 2002). She also presentedsportsmanship and involvement dimensions,the latter of which includes components ofOrgans sportsmanship and civic virtuedimensions. As a final example, Van Scotterand Motowidlo (1996) measured twodimensions of contextual performance by

asking supervisors to rate employee on howlikely they were to engage in certain behaviors.The first dimension, interpersonal facilitation,overlaps with Organs (1988) altruism andcourtesy as well as Morrisons altruismdimension. The second dimension, jobdedication, includes elements of Organs(1988) sportsmanship, civic virtue, andconsciousness dimensions. In recognition tothe overlap among dimensions of OCB,scholars have started considering whetherelements should be combined intoconceptually distinct subgroups. Williams andAnderson (1991), for example, suggested thatOCB directed toward individual (OCBI) isdistinct from OCB directed toward organization(OCBO). Altruism and courtesy are behaviorsthat fit in the former category, whereas,sportsmanship, civic virtue, andconscientiousness fit in the latter category.

It becomes obvious from the abovediscussion that many of the OCB instrumentsin literature have been developed without

explicit theoretical framework. For example,Smith and Colleagues (1983) and Batemanand Organs (1983) instrument did representa comprehensive list of citizenship behaviorsand emphasized a more theoretically groundedapproach for research to proceed rapidly andeffectively. Although theoretical foundationprovided by political philosophy (Van Dyne &Le Pine, 1998) differs from other OCBconceptualization, it is still important to explore

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the construct validity of the OCB measures.

The exploration should include exploratory aswell as confirmatory factor analysis besidesthe assessment of nomological network.Pattern of results may provide preliminarysupport for the construct of the OCBmeasures. Schwab (1980) suggested thatresearchers should try to differentiateconstructs and that construct redundancywould decrease if constructs were developedand tested on the basis of theory. A keyadvantage of this approach is that it avoidstheoretical expansion of the OCB construct. It

is very difficult to say much about hoe thedimensions from different behaviouralframeworks relate to one another in aconstruct validity sense because scholarshave not assessed the extent to which newdeveloped constructs are different from similarconstructs of other existing behavioralframeworks (e.g., Sportsmanship and loyalty).Thus, because the Organs (1988) OCBframework is the only one that has beentreated consistently over a fairly large numberof studies, and because it is highly difficult toconfidently map behavioral elements fromanother framework on to Organs dimensions,we address our research questions by usingmeasures grounded in his framework.

OCB among Contingent and PermanentEmployees

There is very limited research availableon comparison between OCB of contingentand permanent employees; the availableresearch, too, provides contradictory results(e.g., Cappelli, 1995; Chang & Chelladurai,

2003; Feather & Rauter, 2004; Kidder, 1995;Pearce, 1993; Van Dyne & Ang, 1998). VanDyne and Ang, (1998) in a study ofprofessional bankers and hospital employeesfound that contingent workers engaged infewer OCBs and had lower affectivecommitment to their organizations. Theyargued that there would be less pressure forcontingent employees, who receive fewertangible and intangible rewards from their

employing organizations, to perform OCB

when the market is one in which there aresevere shortages of labor and when theirchoice of contingent job status would be morelikely to be voluntary.

On the contrary, Feather and Rauter(2004) argued that in labor markets whereorganizations are downsizing or where thereis an oversupply of jobs in a particular area,workers would be more likely to entercontingent work arrangements involuntarily.Contingent employees on short term contractsmight them perform OCB in the expectationthat their doing so would enhance their imageas valued employees, thereby increasing theirchances of being made permanent withinorganization.

This argument seems pertinent becausecontingent worker also face restrictions in theiropportunities to satisfy work values such assecurity, upward striving and control. In anattempt to compensation, they may engage inOCB that would allow them to achieve goalsrelating to these values, depending on the

importance of these values for self. As Organand Paine (2000) observed, the exchangebasis of contingent or marginal employment,while providing certain apparent advantagesto employer, tend to discourage employeesfrom rendering spontaneous and discretionarycontributions in the form of OCB. Employeeswho work under contingent arrangements, areconsigned to marginal status, or incur unfairtreatment because of their permanent butcaptive status come to vie their psychologicalcontract with the organization as transactional

rather than relational. Evidence suggests thatthe negative effects of contingent and marginalemployment on discretionary contributions canbe mitigated by certain aspects of theemployment relationships. Specifically, theeffects appear to depend upon the extent towhich such relationships are voluntary and thesense of organization as operating with a longrun dynamic toward a microcosm of a justworld.



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Thus, it is important to consider the

motivational functions of OCB for workers withcontingent job status, taking account of thegoal structure of individuals and theexpectations they hold about whether OCBSwill be instrumental to attaining goals that areimportant to them.

Overall, findings of previous researchprovide good support for the OCBS as apotentially reliable and valid measure.However, as noted by Van Dyne, Graham, andDienesch (1994), more construct validityresearch is needed in order to fully establishthe psychometric soundness of the instrument.In this regard three limitations of the previousresearch should be noted. First, althoughclaims of a validated OCB measures havebeen reported, the measures have never beenvalidated for sample of either contingent orpermanent employees. Factorial validity of theOCB measures has been assessed mostlyusing exploratory factor analysis. Now thatseveral deficiencies of EFA are welldocumented (Gorsuch, 1997); CFA on the

other hand, is now widely accepted as ameasure of factorial validity.

Finally, although Chang and Chelladurai(2003) have claimed the evidence of factorialequivalence and invariance across fulltimeand part time samples, hypotheses were nottested directly using simultaneous analysis ofthe data. The literature on OCB suggests thatfactorial structure of this construct may varyacross organizational settings (Chang &Chelladurai, 2003; Feather & Rauter, 2004)the assumption of factor equivalence has not

been directly addressed. The purpose ofpresent research is therefore, to (a) assessthe factorial validity of the OCBS across twosamples using CFA approach to the validationinquiry, (b) to test for equivalence of factorialmeasurement and structure across twogroups.

Method

Sample 1 (Contingent Employees)

Sample 1 included 182 contingentemployees from Nationbal DatabaseRegistration Authority (NADRA) headquarterslocated in Islamabad. NADRA is anindependent corporate body with requisiteautonomy to remain free of political pressureand interventions. It is vested to establish andmaintain multipurpose databases, datawarehouses, networking facilities, interfacingbetween database and to develop and

implement registration systems for the entirepopulation, including foreigners andimmigrants as prescribed by the FederalGovernment. The employees were involuntarycontingent workers on fixed term contract whowould prefer permanent employment in thesame position as and when given the choice.There were 106 (63%) men and 76 (37%)women in the sample. The age range of theparticipants was twenty five to thirty six years(Mean = 22.76, SD = 3.45), the averageorganizational tenure was between five to

twelve years (Mean = 1.40, SD = 0.49), theaverage education of the sample wasgraduation (Mean = 2.60, SD = 0.89). About87.5% participants in the sample were marriedand 12.5% were unmarried. The samplerepresented about 59% data entry operatorsand 41% customer service officers.

Sample 2 (Permanent Employees)

Respondents comprised 508 full timepermanent employees from different areaoffices of Pakistan Telecommunication

Corporation, Islamabad. Approximately 650questionnaires were distributed, 508 werereturned, yielding a response rate of 78.15.Of these 508 employees, 82.5% were men and17.5% were women. 37.2% employees werebetween 26 and 35, while 5.5% were between56. 35 and 37% employees have acquired agraduation and masters level education,respectively, while 10 and 16.9% had

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completed high school and inter level

education, respectively. 19.1% employeesrepresented low management (e.g., assistants,upper/ lower division clerks, steno-typists, junior assistant), 44.9% represented middlemanagement (e.g., administration and humanresource personnel), approximately 17.9%were technical personnel (e.g., engineers,technicians, radio operators, andtelecommunication officers). 5.9% were fromaccounts section, and 12.2% of the sampleheld supervisory positions. 38.2% of thesample had completed 11 to 15 years

organizational tenure while 4.5% employeeshad spent 30 and more years with theirorganization. About 83.1% participants weremarried and 16.9 % were unmarried.

Description of the OCBS:Four dimensionsof the organizational citizenship behaviorscale (Podsakoff et al., 1990) were used toassess the organizational citizenshipbehavior construct. The scale comprisestwenty two items. Each item is answeredusing a five point response anchor

numbered from 1 (Never) to 5 (always).Scores on eight items are reverse coded.Following is the description of dimension ofthe scale.

Generalized Compliance: Discretionarybehaviors reflecting a more impersonal formof conscientiousness that does not provideimmediate help to any coworker, but is ratherhelpful to others involved in the system. Thebehaviors (e.g., punctuality, not wasting time,not complaining insignificant things at work)seem to represent something akin to

compliance with the internalized normsdefining what a good employee ought to do.The scale comprises six items.

Conscientiousness: Discretionarybehavior by an employee that goes aboveand beyond the minimal requirement of theorganization in the areas of attendance,obeying rules and regulations, taking breaks,

working hard and so forth. There are six

items in this dimension.Altruism: Discretionary behavior that isdirectly and intentionally aimed at helpingcoworkers with an organizationally relevanttask (e.g., orienting new workers learn their job, helping them adjust to the workenvironment, assisting coworkers with heavywork load). The eliciting stimulus in otherwords, is someone needing help, as in thefashion of social psychological studies ofaltruism. Thus, this dimension is referred toas altruism and consists of five items.

Interpersonal Harmony: Discretionarybehavior by an employee to avoid pursuingpersonal powers and selfish gains withdetrimental effects on others and theorganization. This dimension consists of fiveitems.

These subscales are combined to form asingle measure of OCB. The OCBS has beenshown to be reliable and valid. Reliabilityindices reported by previous research rangefrom 0.70 to 0.93 (Farh, Earley, & Lin, 1997).

Procedure

Data were collected by distributingquestionnaires accompanied by a coveringletter to employees in their respective sections.Participants were approached through theiradministration and questionnaires weredistributed explaining the purpose of the study.They were assured of the confidentiality of anyinformation disclosed and were told that theinformation provided through questionnaireswill be used for research purposes only and

that no one in the organization would see theirresponses. Participants were left to completethe questionnaire by themselves andcollections were done approximately one hourlater. Some f the questionnaires were sentback by mail since the participants insisted oncompleting them at home. After completion ofdata collection, data were subjected to thefollowing statistical analyses.



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Data Analysis

Data were analyzed in two stages. First,exploratory factor analysis was conductedseparately for each group to investigate theunderlying factorial structure of the OCBS. Theemergent factor structure was then verifiedand confirmed using Confirmatory FactorAnalysis (CFA). In the second stage, factorialinvariance of the OCBS was assessed in asimultaneous estimation of data across groupsincluding tests for equivalence of items andsubscale measurement related to numbers offactors and pattern of factor loadings. All CFAanalyses were based on analysis of covariancematrices using LISREL8.3 (Jreskog &Srbom, 2000). This program providesseveral goodness of fit static to aid in theassessment of the degree to which a proposedmodel fits the observed data. However, thereis no single statistical test that best describesthe strength of a structural models predictionpower. Rather, several measures may be usedto assess its goodness of fit. In LISREL models,these measures are divided into three

categories: measures of absolute fit,measures of incremental fit, and measures ofparsimonious fit (Hair, Anderson, Tatham, &Black,1992).

The measures of absolute fit include theGoodness of Fit Index (GFI) and the RootMean Square Residual. GFI is a non statisticalmeasure ranging in value from 0 to 1 (perfectfit) that represents the overall degree of fit,but is not adjusted for degrees of freedom.Root Mean Square Residual (RMSR) is ameasure of the average of the residuals

between observed and estimated inputvariances. Models with RMSR value below0.10 are considered to be indicative of goodfit.

Measures of instrumental fit compare theproposed model to some baseline model, mostoften referred to as the null model. Thenormed fit index (NFI), Non-Normed Fit Index(NNFI), and Comparative Fit Index (CFI) are

usually used for this purpose. NFI, NNFI, and

CFI values greater than 0.90 are consideredto be the indicative of good model fit. Measuresof parsimonious fit relate the goodness of fitmodel to the number of estimated coefficientsrequired to achieve this level of fit. TheAdjusted Goodness of Fit Index (AGFI) is oftenused to measure parsimonious fit. AGFI is anextension of GFI. It is adjusted by the ratio ofthe degrees of freedom for the proposedmodel to the degrees of freedom for the nullmodel. AGFI value of 0.90 and more isconsidered to evidence for good fit (Hair et

al., 1992). Test for Factorial Invariance.

CFA approach to factor invariance wasused to test the equality of parameterestimates across two groups. Primaryinterest was in testing for equivalence ofinvariant item scaling and latent factor co-variances. Nonequivalent scaling units arean indication that the items are differentiallyvalid across groups (i.e., the perception ofitem content varies across group). Noninvariant factor covariance suggests a

differential factor structure for the constructbeing measured across group ( i .e.,relationships among the underlying factorsvaru across group). This was determined bytesting hypothesis that the parameters ofmodels would be consistent acrosscontingent and permanent employees.

Results

Stage 1 : Test of Factorial Validity

EFA

In the first stage, an explanatory factor

analysis using PCA with varimax rotation wasconducted. The KMO for the data set was 0.70and 0.75 for permanent and contingentsamples, respectively, indicating theapplicability of exploratory factor analysis. TheBartlettS test for sphericity (BS) based on chi-square statistics was found to be significant(651.346, p < 0.000) for contingent and(641.322, p < 0.000) for permanent

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employees. Only factors with eigen values

above 1 and more were extracted. Thisresulted in a four factor solution explaining50.13% of the total variance in permanentemployees sample, while for contingentsample the amount of explained variance was47.33%. the loadings of items after rotationwere evaluated to select items with highsaturation (i.e., greater than 0.3) for inclusionof items in factor interpretation. Item no. 3 crossloaded on two factors for both the samples,while item no. 7 and 8 loaded minimally, i.e.,less than 0.3 for contingent sample and

strongly for permanent sample. All other itemsloaded appropriately on their target factors.

The resulting four factor structure wasdeemed to be most optimal in representing thedata for each group of employees. Ofparticular importance was the fact that exceptfor these three items, most of the items loadedon their respective factors. Table 1 presentsthe results of factor analysis. According to thistable, the first factor that emerged reflectedgeneralized compliance, the interpersonal

form of conscientiousness that does notprovide immediate help to any coworker, butis rather helpful to others involved in thesystem (e.g., punctuality, not wasting time, notcomplaining insignificant things at work).Second factor on the solution reflecteddimension of conscientiousness, that is,discretionary behavior by an employees togoes above and beyond the minimalrequirement of the organization in the area ofattendance, obeying rule and regulations,taking breaks, working hard and so forth.

Third factor indicated behavior that is directlyand intentionally aimed at helping coworkerswith an organizationally relevant task (e.g.,orienting new workers learn their job, helpingthem adjust to the work environment, assistingcoworkers with heavy work load). The fourthand final factor reflected discretionarybehavior by an employee to avoid pursuingpersonal powers and selfish gains withdetrimental effects on others and the

organization. Although the EFA findings

suggest that four dimensional OCB constructunderlies the OCBS, and that three items(mentioned above) are possibly problematicwhen used with particular group of employees,the true test must come from CFA approachto analysis, because EFA is limited in its abilityto (a) yielded unique factor solution and definea testable model, (b) assess the extent towhich an hypothesized model fits the data orsuggest alternative parametrisation for modelimprovement, and (c) adequately test thefactorial invariance across group (Bollen,

1989). In contrast, CFA yields this informationand is therefore, a more powerful test offactorial validity.

CFA

CFA were performed with the data of (a)contingent (b) permanent samples, and (c)both groups combined. The raw data matricesfrom both the groups were used as input fileto generate the covariance matrices for theOCB construct. Four models were estimated.Model I was nul model which served as a

baseline for comparison. Model II was thehypothesized four factor model. This CFAmodel hypothesized a priori that:

a) the responses to OCBS could beexplained by four factors.

b) each item would have a non zero loadingon the OCB factor it is designated tomeasure and zero loading on all otherfactors.

c) these factors would be correlated, and

d) the error terms for each item would beuncorrelated.

Model III was the EFA estimated modelwith item no. 3 cross-loading on two factors;while items 7 and 8 loading differently forcontingent and permanent samples,respectively. Model IV was similar to thehypothesized four factor model but item nos.3, 7, and 8 were deleted from this model.



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These models were tested for goodness

of fit to the data. Results indicated that thefour factor model, in which item nos. 3, 7, and8 were deleted, provided the best fit. The fitof hypothesized four factor model wasadequate for all groups from both a statistical( 2) and practical ( 2/df, CFI. GFI, and NNFIvalues) view. These results are summarizedin table 2. Given both substantive andstatistical considerations, this model wasdeemed to be the most optimal in representingthe data for each group of employees. Tocompare the difference between the estimated

and hypothesized models, differences in 2

were evaluated. Because this difference isitself 2-distributed, with degrees of freedomequal to differences in degrees of freedom (df)it can be tested statistically; a significant 2

indicates a substantial improvement in modelfit. Results in table 2 indicate a highlysignificant improvement in fit between modelthree and four for each group of employees.This model appears to be the best fitting modelbased on the GFI, CFI,RMR. NNFI, and 2 /dfratio. These findings lend further credence tothe fact that item nos. 3, 7, and 8 may not bepsychometrically sound. Based on results fromEFA and CFA analyses, it was consideredreasonable to proceed with testing ofequivalency of item measurement acrossgroups; Model 4 provided the baseline modelfor these analyses.

Stage 2: Test for Factorial Invariance

In an effort to further explore theconceptual equivalence of the OCBS acrossgroups, two component measures were

examined for each employment group (a)the parameter estimates and (b) the itemreliabilities. The parameter estimates for thebest fitting model are presented in Table 3. Allof the lambda coefficients were statisticallysignificant and positive. Also, inspection of theitem reliabil ities (squared multiplecorrelations), for the observed indicatorsrevealed that latent variables well explainedthe item variance across the two groups.

Overall, findings in table 3 indicated the

conceptual equivalence of the constructsacross the employment sample group thusleading to the conclusion that contingent andpermanent workers responded to the saleitems in a similar conceptual frame ofreference. However, the fact that item nos.seven and eight loaded differently for thecontingent and permanent samples in no waylessened the importance of testing forequivalence of the OCBS across employeesgroups (Byrne, 1989). Primary interest intesting for equivalence was the question of

invariant item scaling units and factor co-variances. Non-variant scaling units are anindication that items are differently valid acrossgroups (i.e., the perception of item contentvaries across group); non-variant factor co-variances suggest a differential structure forthe construct being measures across groups(i.e., relations among the underlying factorsvary across groups). To test for the invariance,following procedures involving partialmeasurement invariance demonstrated byByrne (1989), a model was specified in whichcertain parameters were constrained to beequal across groups and then comparing thatmodel with a less restrictive model in whichthese parameters were free to take on anyvalue. 2 between competing modelsprovided a basis for determining the tenabilityof the hypothesized equality constraints, asignificant 2 indicating non-variance.

Equivalence of Items

All items were found to be equivalentacross group except for item nos. 3, 7, and 8.

item no, 3 cross loaded on two factors, whileitem nos. 7 and 8 were non-equivalent acrosstwo employees group. Evaluation of itemloading revealed substantial differentiation ininterpretation of these two items by contingentand permanent employees, these two itemswere found to be invariant indicating thatcontingent employees interpreted these itemssomewhat differently from their permanentcounterparts. To derive further insight

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ContingentSample

Permanent

Sample

Items

COMP

CONS

A

LT

INT

COMP

CONS

ALT

INT

1.attendanceatwork

.79(.92)

.22

.13

.14

.71(.67)

.20

.13

.15

2.givesadvancenotice

.75(.65)

.23

.12

.09

.79(.65)

.13

.02

.09

3.coasttowardstheendofday

.34(.34)

.32(.38)

.17

.13

.27

.28

.17

.03

4.undeservedworkbreaks

.15

.46(.75)

.11

.22

.11

.59(.78)

.15

.10

5.Personalphone

.09

.69(.81)

.03

.23

.04

.67(.74)

.09

.21

conversations

6.complaininsignificantthings

.14

.56(.38)

.13

.10

.11

.54(.72)

.17

.10

7.passesinformationtoco-w

orkers

.24

.29

.23

.21

.54(.56)

.27

.29

.22

8.protectorganizationalproperty.

.23

.11

.16

.07

.43(.57)

.17

.16

.02

9.adherencetoinformalrule

s

.62(.56)

.09

.22

.19

.67(.63)

.02

.28

.14

10.makesinnovativesugges

tions

.73(.85)

.26

.23

.09

.79(.74)

.22

.29

.06

11.meetsperformancerequirements

.02

.73(.57)

.12

.19

0.09

.72(.82)

.10

.17

12.volunteertodothingsreq

uired

.67(.53)

.11

.09

.09

.63(.73)

.09

-08

.15

13.usespositionpower

.09

.09

.02

.81(.90)

0.07

.08

.09

.86(.87)

14.takepersonalinterestinothers

.13

.08

.75(.81)

.07

0.19

.05

.70(.69)

.05

15.usestacticstoseekpers

onalinfluence.14

.21

.02

.70(.87)

.11

.25

.09

.71(.85)

16.takescreditandfightfierc

ely

.24

.11

.15

.65(.57)

.21

.12

.05

.67(.77)

17.speaksillofsupervisor

.10

.13

.19

.59(.66)

.11

.00

.09

.56(.55)

18.speakillofcolleagues

.17

.09

.20

.61(.48)

.10

.12

.23

.51(.58)

19.assistsnewworkersadju

sttotheirjobs..07

.07

.52(.87)

.11

.01

.13

.53(.67)

.03

20.Coordinateswithco-work

ers

.08

.25

.56(.85)

.16

.02

.22

.54(.45)

.19

21.willingtohelpco-workers

.11

.03

.60(.89)

.12

.09

.08

.65(.73)

.08

22.helpscoworkerswithhea

vyworkloads.18

.10

.70(.80)

.12

.08

.17

.72(.70)

.04

Mean

16

16

1

5.09

9.79

11.29

17.2

15.53

9.62

SD

2.06

2.48

2

.57

3.14

2.98

5.88

2.75

2..18

Note:COMP=Complian

ce;CONS=Conscientiousness,ALT=Altruism;INT=InterpersonalHarmony;

Loadingsof>0.30arepresentedboldfaced;SignificantCFAloadingsarereportedinparentheses.

Table1:ExploratoryandCo

nfirmatoryFactorLoadingsoftheOrganizationalCitizenshipBeha

vior

Scale



11/16

59

Model c2 df c2a df c2/df rmr GFI CFI NNFI

Permanent Sample

I. Null model (all 22 items) 1879.59 406 4.62 - - - -

II. Hypothesized 4-factor 416.1 54 7.7 0.06 0.86 0.89 0.9model

III. EFA estimated model b 384.43 53 31.67*** 1 7.25 0.06 0.87 0.89 0.91

IV. Model II with item nos. 331.85 51 52.57*** 2 6.5 0.06 0.9 0.92 0.9

3,7,8 deleted

Contingent Sample

I. Null model (all 22 items) 1605 528 3.04 - - - -

II. Hypothesized 4-factor 182.51 54 3.07 0.1 0.85 0.67 0.6model

III. EFA estimated model b 168.98 53 13.69* 1 3.18 0.1 0.86 0.68 0.6

IV. Model II with item nos. 135.65 51 33.33*** 2 2.65 0.92 0.77 0.7

3,7,8 deleted

Combined Sample

I. Null model (all 22 items) 1697.5 573 2.96

II. Hypothesized 4-factor 629.88 55 11.45 0.05 0.85 0.9 0.88

model

III. EFA estimated model b 543.07 53 86.81*** 2 10.24 0.04 0.86 0.91 0.9

IV. Model II with item nos. 510.68 50 32.39*** 3 10.21 0.04 0.9 0.92 0.9

3,7,8 deleted

Table 2 : Model Fitting Indices across samples

a represents difference in 2 from the competing model; b item 3 cross-loading on two factors;Items 7 and 8 loading differently for contingent and permanent samples, respectively, *** p

Ocb,Validating Factorial Structure and In Variance Among Employees

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