Construct validity is defined as the degree to which a measure assesses the construct it is purported to assess (Peter, 1981, p. 134; also see Schwab, 1980). In this section, the construct validity of the diversity management scale was examined by assessing convergent, discriminant and nomological validities.
4.8.1 Content Validity
Content validity of the diversity management scale was based on theoretical
expectations, and upon expert opinions of researchers and practitioners (e.g. Shin, Collier & Wilson, 2000). As noted earlier, all scale items were taken from the literature and from the in-depth interviews with HR/diversity managers. Although the assessment of content validity is a subjective process (Carmines & Zeller, 1979), the comprehensive content (i.e. the items within the scale) of the scale derived from an extensive literature search, in-depth interviews and the use of expert judges provided support for acceptable content validity (DeVellis, 2003; Spector, 1992).
4.8.2 Convergent and Discriminant Validity
Convergent validity refers to the degree of agreement between two or more measures
of the same construct. Evidence of convergent validity was assessed by three measures: item reliability; construct reliability (Cronbach alpha); and average variance extracted (AVE – Fornell & Lacker, 1981). Item reliability was evaluated by the size of the loadings of the measures on their corresponding constructs. According to Falk and Miller (1992) and Chin (1998), most of the loadings should be at least .60, and ideally .70, or higher. This indicates that each measure is accounting for 50% or more of the variance in the underlying latent
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variable (Bagozzi, 1994; Fornell & Larcker, 1981; Hair et al., 2006). Given that all the items loaded highly (i.e. > .60) on the diversity management factor demonstrates the scale’s convergent validity (Fornell & Lacker, 1981). Table 4.4 shows the item loadings for the measurement model, indicating adequate convergent validity. Further, as mentioned earlier, the Cronbach alpha’s assessing reliability of each factor was deemed adequate. Alpha for the diversity management practice scale was .93, which is above the typical .70 cut-off (Nunnally, 1978). Finally, the AVE score for the diversity management practice scale was .65 (see Table 4.4). According to Fornell & Larcker (1981), convergent validity is established if the value of the variance extracted exceeds .50 for a factor. Taken together, my analysis demonstrates that the newly developed diversity management practice scale is uni- dimensional and has a high degree of convergent validity.
Table 4.4 Measurement Model Items
Construct items Loadings Average variance extracted Cronbach alpha .65 .93 DMP8 .79 DMP10 .66 DMP11 .80 DMP12 .88 DMP13 .87 DMP14 .82 DMP15 .79 DMP18 .63 DMP20 .71
Discriminant validity is the extent to which a measure is indeed novel, and not simply
a reflection of some other variables (Churchill, 1979). Hence, assessment of discriminant validity requires comparison with other constructs. Campbell and Fiske (1959) argue that constructs can be invalidated by too high correlations with other constructs from which they
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were intended to be differentiated (p. 81). In order to assess the discriminant validity of the diversity management practice scale (and as previously noted), data were collected on a number of variables theorised to relate to DMP. These variables are diversity management (Pitts, 2009) and diversity climate (Mor Barak, Cherin & Berkman, 1998; DeNisi & Gonzalez, 2009) (see Chapter Three for construct definitions). One way by which discriminant validity can be demonstrated is through the magnitude of the correlations between the measure of interest and other measures that are supposedly not measuring the same variable (Mor-Barak et al., 1998; Heeler & Ray, 1972). The objective is to confirm that each item correlates more strongly with its respective factor than with all other factors (indicating that the item ‘discriminates’ its own factor from others).
Accordingly, discriminant validity was assessed by Fornell and Larcker’s (1981) test. According to these authors, a construct may be considered to have adequate discriminant validity if the square root of the AVE for each construct is larger than the correlation between that construct and any other construct in the model (Chin, 1998; Fornell & Larcker, 1981). As shown in Table 4.5, all constructs in the estimated model fulfilled this condition of discriminant validity. The relatively high variance extracted for each factor, compared to the correlations between constructs, offers evidence of discriminant validity.
Table 4.5 Descriptive Statistics and Correlation Among Construct Scores
DMP Diversity Management Diversity Climate
DMP .81
Diversity Management .47 .80
Diversity Climate .12 .58 .87
M 2.55 3.11 3.53
SD 1.01 0.95 1.03
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4.8.3 Nomological validity
Nomological validity refers to the ability of a scale to behave as expected with respect
to some other constructs to which it is related (Churchill, 1995). This type of validity is based on hypothesised relationships between theoretical causes and effects of the test construct. There are well-grounded theoretical reasons to expect a positive association between diversity management and attitudinal work outcomes, such as organisational commitment, job satisfaction and perception of overall justice (e.g. Pitts, 2009; McKay et al., 2007; Magoshi & Chang, 2009). Thus, in the current context, nomological validity would be demonstrated if diversity management positively and significantly related to job satisfaction and organisational commitment. From a social exchange perspective, we can expect that an employee who perceives that the organisation values diversity management by its implementation of diversity management practices is more likely to reciprocate with a positive attitude, such as organisational commitment (cf. Pitts, 2009; McKay et al., 2007; Magoshi & Chang, 2009).
As shown in Table 4.6, diversity management positively related to organisational commitment (r = .35, p < 0.001) and job satisfaction (r = .43, p < 0.001), suggesting evidence of nomological validity for the proposed diversity management practice scale.
Table 4.6 Means, Standard Deviations, and Inter-correlations
Variable M SD α 1 2 3
(N = 170)
1. Diversity management practices 22.91 9.04 .93 -
2. Job satisfaction 19.42 5.33 .85 .43** -
3. Organisational commitment 17.83 5.58 .83 .35** .69** -
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In summary, the findings suggest evidence for convergent validity, discriminant validity and nomological validity, indicating that the newly developed 9-item uni- dimensional diversity management practice scale has adequate psychometric properties (see Appendix 7 for final DMP scale items).