SCALE DEVELOPMENT

The goal of this chapter is to develop scales to measure instrumental and terminal materialism as an individual difference variable. Richens and Dawson (1992) give several reasons for the importance of measuring materialism as an individual difference variable. First, insight at the individual level may provide insight at the cultural level. Second, hypotheses at the individual level are easier to test than at the cultural level. Third, the relationship between materialism and various marketing activities can be measured at this level. In addition, Belk (1985) suggests that measuring materialism is important for examining the human and social impact of this aspect of consumer behavior.

Churchill’s (1979) scale development framework along with additional scale development refinements (e.g., Mowen and Voss 2008; Gerbing and Anderson 1988) was utilized for this section. The eight steps proposed by the Churchill (1979) model are followed: domain specification, item generation, data collection, measure purification, data collection, reliability and validity assessment, and norm development. These steps are discussed in detail below.

Domain Specification

In Churchill’s (1979), scale development framework, the first step is to specify the domain of the construct. In domain specification, “the researcher must be exacting in delineating what is included in the definition and what is excluded” (Churchill 1979, p.

67). As suggested by Mowen and Voss (2008) a multiple domain problem exists when items measuring a construct are taken from different domains so that it measures two constructs instead of one. As discussed in the literature review, the prior literature on definition construction was considered when defining instrumental and terminal materialism to ensure that these issues were addressed. The issues of abstraction, position in a hierarchical net (Mowen and Voss 2008), and defining in terms of antecedents and consequences (Mowen and Voss 2008; MacKenzie 2003) were

considered when defining the new constructs. Thus, as proposed in the literature review section, terminal materialism is defined as the importance of material possessions in gaining status classification among others. In contrast, instrumental materialism is defined as the importance of material possessions as resources to accomplish tasks. Instrumental materialism is proposed to reside at the elemental level in the 3M Model (Mowen 2000) while terminal materialism is proposed to reside at the compound level. These definitions identify the domains of the constructs and distinguish the new

constructs from prior conceptualizations of materialism. Item Generation

The next step in this model involves item generation. Past literature has provided guidelines for developing items. MacKenzie (2003) suggests that three things should be considered when measures of a construct are developed: (1) that all key aspects of the conceptual definition are reflected in the measures, (2) that items do not capture anything outside of the conceptual domain, (3) and that the items are properly worded. Teas and Palan (1997) suggest two additional considerations when assessing the theoretical meaningfulness of concepts: intensional vagueness and extensional vagueness. Mowen

and Voss (2008) propose a matching principle for item generation that involves abstraction-level matching and within-level matching. Abstraction-level matching involves selecting items from the same level of abstraction as the construct’s definition while within-level matching suggests that items from two different constructs at the same level should not be combined. Mowen and Voss (2008) also suggest that scales should consist of about four to eight items.

These guidelines provided by past research were utilized in the item generation process. Initial items were designed to capture the entire domain as specified by the definition but not include items that were outside the domain. Twenty-six items for instrumental materialism were generated. For terminal materialism, items from previous scales were utilized if they fit the definition and additional items were generated based on the definition. Ten previous items were taken from Richins and Dawson (1992) and the four items from the Mowen (2000) scale were also used. Additional items were

generated based on the definition resulting in a total of 31 items. These items were assessed by a panel of academics in the field of marketing and are shown in the

Appendix. The panel of five researchers in the area of consumer behavior was given the definitions and items for terminal and instrumental materialism and was asked to rate on a scale of 1-5 how well the items represented the given definitions. Items were then selected for the final survey based on their rating.

Item Refinement and Reliability

After items were generated, they were tested and refined through data collection in two different surveys. The first data collection survey contained 30 items for terminal materialism and 20 items for instrumental materialism. Two hundred seventy-five upper-

division business students at a Midwestern university completed the survey for course credit. Respondents were assured anonymity and confidentiality and given unlimited time to complete the survey. Fourteen surveys contained significant acquiescence (yea- saying and nay-saying) on the second page of the survey. These surveys were identified from the raw data where the same number was recorded for the majority of the second page. These surveys were dropped from the analysis.

To refine the instrumental materialism scale, it was analyzed with principle component factor analysis. Five factors emerged with eigenvalues above one, accounting for 58.7% of the cumulative variance. Communalities for the items were low; of the 20 items, only 2 were above .7 and 11 were below .6. This lack of correlation was also apparent in the correlational matrix; no correlation between the 20 items was above .6. Because of the weak results, it was decided that none of these items were suitable for further analysis. Thus, for the second round of data collection, new items were

generated. To remedy the deficiencies in the first items, seven items were generated that were closer in verbiage with four items asking about importance of possessions and three items asking about the primary purpose of acquisition. These items are shown in Table 1. It was believed that these items were more cohesive and would thus hold together better.

TABLE 1