Credibility, according to Janesick (2000) has tended to revolve around the trinity of validity, reliability and generalisability. Janesick observes that for qualitative researchers, there is no need to use the terms validity, reliability and generalisability, because these are terms that more correctly apply to the quantitative paradigm. Instead, she proposes replacing those words with qualitative referents that more accurately capture the complexity and texture of qualitative research. Pioneers of mixed-method studies on the other hand, proposed other terms to incorporate both quantitative and qualitative orientations.
3.7.1 Validity and reliability
Validity and reliability are two aspects of credibility. Reliability in quantitative research simply means that the research findings can be repeated. To increase research reliability, research pioneers recommend using pretests, pilot studies and replication (Neuman, W Lawrence 2000). In the case of the survey employed in the current research, as mentioned before, “pre-testing using Panel of experts /judges” was employed. To further enhance the reliability of the research, equivalence reliability as explained by Neuman (2000) was applied, by using several items in the questionnaire to measure the same constructs. In addition, replication was considered for one question (more details have been reported in the findings chapter). Issues of reliability are much more subjective when it comes to qualitative research. Some have argued that, in the qualitative part, if the research produces convincing results, then it will be reliable (Golden- Biddle & Locke 1993; Maxwell 2002).
The researcher here, acknowledge Denzin’s (1989, P.32) point that in triangulation research the “Interpretation will always be provisional and somewhat incomplete, to be taken up anew when the researcher returns to the field”. In the case of qualitative research, Janesick (2000) confirms the possibility of different interpretations of an event and claims that there is no single ‘correct’ interpretation. Similarly Janesick (2000) asserts that there is no one best system for data analysis in qualitative research. Using a dance metaphor, whereby no one can choreograph an individual dance, she shows that it is only the researcher who can interpret data that emerges from
qualitative research. Like the choreographer, the researcher needs to find the most effective way to write the narrative, and to convey the meaning of the study to the reader. According to McMurray et al. (2004, P.249) therefore, “Regardless of what route you use in the analysis of your notes and observations, the accuracy with which they are interpreted is the measure of the quality of your research”.
Validity, as defined by Collis and Hussey (2003, P.58), is “The extent to which the research findings accurately represent what is really happening in the situation”. Within the multi-method context Cresswell and Plano Clark (2007, P.146), define validity as “The ability of the researcher to draw meaningful and accurate conclusions from all of the data in the study”. Teddlie and Tashakkori (2003) however, introduce the term inference quality as a mixed-methods term, to cover the quantitative term internal validity, and the qualitative terms trustworthiness and credibility of interpretations. According to them, inference quality indicates the degree of excellence of the inductively and deductively drawn conclusions and interpretations of a study which, includes both qualitative and quantitative approaches. To determine the accuracy of a study’s outcome they suggested the consideration of two criteria namely, design quality and interpretive rigor. Design quality as they point out, means within-design consistency, and includes the use of a whole set of criteria from both the quantitative and qualitative orientations, to determine the methodological rigor of the mixed-method research. Interpretive rigor then, involves the evaluation of the accuracy or authenticity of the conclusions, and includes the conceptual consistency and interpretive agreement (or consistency) and interpretive distinctiveness.
There is recognition within the research literature that using an integrated approach can strengthen the comprehensiveness or reliability and validity of a study (Shih 1998). Triangulation, as suggested by Denzin (1989), was employed in this research project to enhance the validity or trustworthiness of findings, by eliminating the researcher’s personal biases. According to Denzin (1989, P.26) “The combination of multiple methods in a single investigation will better enable the sociologist to forge valid propositions that carefully consider relevant rival casual factors”. Kemper et al. (2003, P.284) assign the use of purposive sampling procedures as evidence for the enhancement of inference quality (internal validity or trustworthiness) in mixed- method studies.
On the other hand, there are arguments within the literature that the validity is high in interpretivist research. According to Collis and Hussey (2003, P.59) for example, “A phenomenological paradigm is aimed at capturing the essence of the phenomena and extracting data which is rich in its explanation and analysis. The researcher’s aim is to gain full access to the knowledge and meaning of those involved in the phenomenon and consequently validity would be expected to be high under such a paradigm.
3.7.2 Generalisability (The external validity)
Previously, many qualitative researchers considered generalisation to be irrelevant to the goals of interpretivists. For example, Denzin (1983, P.133) noted that “ The interpretivist rejects generalisation as a goal and never aims to draw randomly selected samples of human experience”. For the intepretivist, as Denzin further pointed out, every topic must be seen as carrying its own logic, sense of order, structure, and meaning. Schofield (1993), however, referred to the growth of interest in generalisability among qualitative researchers, signifying that although the classical view of external validity, i.e. producing laws that apply universally is not the standard or goal of qualitative research, there is an emerging recognition that the studies in one situation can be used to speak to, or to help form a judgment about other similar situations. This understanding, as Schofield points out, led to attempts to reconceptualize generalisability in a way that was useful and appropriate for this type of research work. Referring to a number of alternative concepts such as ‘fittingness’, ‘translatability/ comparability’ and, ‘naturalistic generalisation’, Schofield highlights the consensus among them on the importance of providing sufficient information about the components of a study, including the entity studied, the context in which the studies are conducted, and the setting to which one wishes to generalise, to enable one to search for the similarities and differences between the situations. According to Neuman (2006, P.91), interpretive research is idiographic and inductive. It means that the bulk of the report is a detailed description of a social situation or setting. This thick explanation therefore, helps the researcher to provide generalisations and gives the reader a feel for another’s social reality.
In the mixed-method area however, Teddlie and Tashakkori (2003, P.42) suggest use of the term inference transferability, as an umbrella term which incorporates both the
concepts of external validity and transferability from the quantitative-qualitative nomenclature. Arguing that all inferences have some degree of transferability, they remind the reader that transferability is relative. That is, no research inference is fully transferable to all settings, populations or times. They further refer to the assumption held by a number of scholars, that the inferences generated in mixed-method studies are more transferable than the conclusions merely derived from their quantitative or qualitative components.