PWMF Validation Method

„Validation‟ is ensuring about the credibility by strengthening confidence of research findings (Patton, 2003). Further, validation aims to enhance understanding and explanation (Cronbach, 1984). Messick (1989) mentioned that “validation is essentially

a type of scientific inquiry, that a validity judgement is an inductive summary of all available information, with issues of meaning and interpretation central to the processes” (Mishler, 1990, p.418). Therefore, these views suggest that validation is a judgemental process which helps to enhance credibility, explanation and understanding research findings.

Mishler (1990, p.415) noted that “validation is a process through which a community of researchers evaluates the trustworthiness of a particular study as the basis for their own work”. Bernard (1994) argued that validation is the collective judgement of the scientific community about the validity of a particular concept and its measures. A similar view can be seen in the literature to the role of researchers and experts‟

judgements in establishing the validity of findings (Linconln and Guba, 1985; Cronbach, 1988; Straub, 1989; Patton, 2003). Validation process also can involve getting reviews from respondents those who responded at first place for the research (Lincoln and Guba, 1985; Patton, 1990). Furthermore, if respondents are provided an opportunity to examine and comment on the findings, it allows researchers to learn a great deal about the accuracy, completeness, fairness about the final research outcome presented (Patton 2003). Besides, Glesene (1999) described how important study‟s respondents‟

feedback to confirm the findings that may help:

 to verify that the research findings have reflected perspective of respondents;

 to inform the problematic sections that, if published (e.g. could be personal or political reasons); and

 to develop new ideas and interpretations.

Therefore, validation refers to evaluation and judgement of the main outcome of research (or the developed instrument) by the involvement of the research community, experts in the field and study‟s respondents.

Researcher‟s values and decisions involve in the theme identification process. As such there is always ground for arguments on the validity of identified themes and arrived conclusions (Ryan and Bernard, 2003). As literature indicates, the potential way of addressing such arguments on the validity is to outline in details of the techniques used in the research process, whereas particular reader has the opportunity to understand the context of the research findings and conclusions (Agar, 1980; Patton, 2003).

Therefore, the adopted research methodology of this study outlined a number of attempts that were made throughout the research process to ensure richness of validity of findings (e.g. selection of data collection methods, sampling, data analysis, dealing with research bias).

Themes identification and refining itself do not produce a unique solution for the issues investigated in the research (Ryan and Bernard, 2003). Therefore, there are as many ways of seeing and arranging them to gain useful application (s). One such potential way is proposed (i.e. PWMF) in section 2.10.1 by interrogating key themes emerged from this research. Subsequently, there is still question of validity after transformed the findings of the study to a different format. How does one know if the proposed PWMF and the themes identified in it are valid? Based on the above discussion, the validation process of this study involves evaluation and judgement of the developed PWMF by the involvement of (1) researcher (i.e. Initially, the development of PWMF by identifying and synthesising key themes and then analysing the responses of validation respondents); (2) research community (i.e. PWMF refinement discussions with construction management researchers in Civil and Building Engineering department, Loughborough University); and (3) study‟s respondents (i.e. PWMF validation questionnaire and interviews with PM, SM and QS). The subsequent section describes the process to be adopted for the proposed PWMF validation.

The aim of the framework validation is to refine and examine the appropriateness of the proposed PWMF for D & B projects and to discuss the framework implementation strategy. In light of achieving the above, the four specific objectives of the evaluation were set out: determine the clarity and information flow of the proposed PWMF;

determine the information flow and appropriateness of the four PWO and their detailed contents; examine the appropriateness and practicalities of the proposed improvement measures; and identify a potential implementation strategy for the proposed PWMF.

The validation process consisted of three stages: PWMF refinement pilot study (i.e.

PWMF pre-validation refinement discussions with construction management researches, Loughborough University), validation questionnaire and face-to-face semi-structured interviews (i.e. a PWMF validation questionnaire followed by a series of semi-structured interviews with PM, SM and QS) (refer to section 2.10.2.3 for the PWMF validation sampling method). While semi-structured interviews were considered as the main validation approach, pre-validation questionnaire was used as a tool to get respondents‟ attention about the developed PWMF prior to the PWMF validation interviews. The data generated both through PWMF validation semi-structured interviews (qualitative) and PWMF validation questionnaire (quantitative) was used in the framework validation data analysis as both approaches provided a solid basis to framework validation. Consequently, PWMF was finalised by amalgamating corrective

actions and changes (Figure 2.5 stage 3) that arose from the results of validation data analysis.

2.10.2.1 PWMF validation questionnaire

The aim of the pre-validation questionnaire was to refine and improve PWMF in terms of clarity, information flow, and contents with regard to generic and detailed components. As shown in Appendix 2.5, the three page questionnaire comprised five sections: background information (respondents‟ experiences, designation); High-level PWMF validation (clarity and information flow); Four Low-level PWMF validation (improvement measures); implementation strategy and further thoughts. Additionally, two separate questions were forwarded to validation questionnaire respondents: first, to assess the PWO clusters in terms of waste generation severity by ranking them 1 to 4; and second, to assess the impact (High, Medium, Low) that each PWO cluster has on waste generation.

2.10.2.2 PWMF validation semi-structured interview template

The aim of the semi-structured validation interviews was to refine and examine the appropriateness of the proposed PWMF (i.e. in terms of issues raised from the validation questionnaire such as clarity, information flow and improvement measures) and to discuss the framework implementation strategy. Interview questions were in four sections. The first section was aimed at a High-level PWMF validation (clarity of the structure, information flow, appropriateness of the four PWO clusters and their respective contents and appropriateness and practicality of the proposed target areas/

parties for improvements). The second section was focussed on Low-level PWMF components validation [strengths, weaknesses and suggestions (if appropriate) related to waste origins and improvement measures proposed under each PWO cluster]. The third section was aimed to investigate PWMF implementation strategy. The fourth section was focussed on further thoughts: other issues/suggestions that were pertinent to improve the proposed PWMF (Appendix 2.5).

2.10.2.3 PWMF validation respondents sampling method

A similar sampling approach as that discussed in section 2.7.2 was adopted to select respondents for PWMF pre-validation questionnaire and PWMF validation semi-structured interviews. Nine out of seventeen respondents from the second stage data collection (i.e. semi-structured interviews) agreed to participate for the third stage of the study. Out of which, only six (out of nine) respondents were available when they were

contacted for interviews: two respondents each from PM, SM and QS. However, as shown in Table 2.10, eight respondents were involved in PWMF validation process.

While six out of eight respondents were involved in the study during the previous two data collections (i.e. questionnaire survey and semi-structured interviews), an SM and a PM were joining the study for the first time.

Table 2.10. Composition of PWMF validation respondents sample

PWMF Validation Respondents Total

by company Contractors Quantity surveyors

4 2 6

by Profession Procurement managers

Sustainability managers

Quantity surveyors

3 3 2 8

2.10.2.4 PWMF refinement pilot study

The PWMF refinement pilot study was aimed to refine the developed PWMF in terms of framework structure and English, clarity of contents, clarity of information flow and gather further suggestions for improvements (Appendix 2.5). Seven construction management researchers (at Department of Civil and Building Engineering, Loughborough University) were involved in the refinement pilot study discussions. The PWMF was further refined based on received comments from the refinement pilot study: for instance formatting and typological errors.

2.10.2.5 PWMF validation process

Five documents were disseminated (i.e. emailed) to eight selected respondents: a covering letter (aim and framework overview), a PWMF pre-validation questionnaire (respondents were asked to complete before the interview date), a PWMF validation interview template, a proposed PWMF and consent form. A similar interview approach as discussed in section 2.8.3 was used to conduct validation interviews. Completed PWMF pre-validation questionnaires were collected before the interview and given responses to the questionnaire were also considered during the interview instances where further explanations are essential. The time allocation was 60 minutes for each interview: High-Level PWMF validation (10 minutes); four Low-level PWMF validation (25 minutes); PWMF implementation strategy (20 minutes) and further thoughts (5 minutes). Six interviews were conducted over approximately three weeks during November 2008 to January 2010.