Data Collection- Questionnaire Development

The survey to be used comprised of several metrics, which will be discussed in this section. As appropriate questionnaire design is vital to its success as a data collection tool, the following section shall cover the creation of the survey used in this study, paying particular attention to the design and development of the original situational scale metric, and will lead into the analysis of the data yielded by the questionnaire metrics.

With theoretical models to form the basis for the research, it is necessary to determine the constructs of interest and their composition, to ensure hypotheses may be tested. It is important to ensure that metrics used to measure constructs are both meaningful and robust, so an

approach suggested by Churchill (1979) on metric design was adopted to form the basis for scale development. These discriminative stimuli scales were created based on a review of extant literature, and developed following the iterative process outlined in figure 3.1 below suggested by Churchill (Churchill 1979), to ensure rigour and validity of the metrics. This involved the

154

generation of valid and feasible questionnaire items; collection of data; ‘measure purification’

(Bristow and Mowen 1998; Bristow and Mowen 1998), involving the improvement of

ambiguous items and removal of redundant and duplicate questions as part of the pilot study of the questionnaire. Then reliability and validity were assessed. As a part of the development process, the questionnaire was repeatedly validated and analysed to ensure both accuracy and reliability, as a measure of the degree to which shopping situation impacts on different consumers

Subsequent to Churchill’s widely cited paper, discussions of instrument development have highlighted inadequacies of instrument validation, and concerns that “the primary and prior value of instrument validation has yet to be widely recognised” (Straub 1989 p147). Though originally discussed in the context of research in Management Information Systems, more recent discussion has focussed on scale development and validation in broader areas including

behavioural research (MacKenzie, Podsakoff et al. 2011). They summarise the limitations in previous scale development procedures as being threefold. The first is that the construct domain

Source: adapted from

155

is not adequately defined and considered properly in terms of appropriate conceptual

definitions. The second is that the measurement model is rarely correctly specified, in particular, the latent (unobservable) constructs are not related with their indicators. Finally, that previous studies have failed to use (construct validity) techniques already established to ensure the scale metrics developed are actually measuring the conceptual constructs the claim to measure (MacKenzie, Podsakoff et al. 2011). Even though Churchill’s original procedural framework for scale development included the necessary ‘assess validity’ stage, MacKenzie et al (2011) suggest that few studies appropriately consider this. Issues surrounding validity will be considered later on. MacKenzie et al put forward an overview of procedure for developing scales, which bears some similarity with Churchill’s earlier procedure, with some additional detail in terms of validation (figure 3.2). (Straub 1989)

Conceptualisation Develop a conceptual Step 1

definition of the construct

Model Specification Step 4

Step 3

Norm Development Step 10

Step 3 Develop norms for the scale

156

Churchill’s procedure shall be used to structure the discussion around scale development, with stages first acknowledged, before considerations for scale development for the two studies are presented.

3.3.1 Specify Domain of Construct

Principles of Construct Definition

Churchill defines the first step of scale development as specifying the domain of the construct.

A ‘construct’ is considered ‘abstract and latent’, rather than observable and concrete (Nunnally and Bernstein 1994), because the variable is literally constructed by the researcher. This means establishing the extent and focus of the domain- what the construct does and does not contain.

MacKenzie et al (2011) recognise ‘definition of the conceptual domain of the construct’ as the first stage of the scale development procedure, wherein the researcher must “specify the nature of the construct and its conceptual theme in unambiguous terms and in a manner that is consistent with prior research” (p298), highlighting also how the construct differs from related constructs. Along with Churchill’s second step (generating a sample of items), the first step involves examination of relevant literature in the area. In this instance, literature is used to determine how the construct has been defined by previous researchers. This should ensure the defined constructs are theoretically grounded, highly pertinent, and importantly, specific to the study at hand. He illustrates that while the satisfaction constructs ‘expectations’ and

‘consequences’ have been well defined and widely used (Howard and Sheth 1969), what exactly should the marketer attempt to assess on these constructs? This come down to further reading, but also contextually specific attributes. The domain of the ‘expectations’ construct might be very different for a study on shopping centre satisfaction for example, compared with one examining satisfaction with a car purchase. Critical dimensions for one (after sales service, durability, status) have little relevance to the other. Specifying domain of construct, ensuring it is relevant given the application theoretical construct (through thorough review of literature) to the research at hand, is therefore of vital importance. This will be true for the constructs under investigation in this research.

MacKenzie et al (2011) suggest that when specifying the construct domain, one should examine how this construct has been used in prior research, specify the nature of the construct’s

157

conceptual domain in terms of the entity to which the construct applies, and the property the construct represents. Then the conceptual theme of the construct should be specified, and finally the construct presented in unambiguous terms.