This paper provides examples of internal and external validity from empirical qualitative peer-reviewed academic articles relating to project management in the oil and gas industry. The paper is divided into four sections highlighting internal validity, inferential external validity, theoretical external validity, and a discussion.
Internal validity refers to the ‘truth value’ of the research, allowing the researcher to demonstrate a level of truth or believability in their research (Newman & Benz, 1998), specifically referring to “the causal relationships between variables and results” (Gibbert, Ruigrok, & Wicki, 2008, p. 1466). Olsen et al. (2008) address internal validity as follows:
Regarding internal validity, cause-effect relationships between specific variables may be difficult to reveal, and we cannot exclude other explanatory factors. However, since our objective is to provide new knowledge and broaden our understanding of the interplay of the three governance mechanisms, we should be able to make some inferences (p. 5).
Inferential external validity is otherwise called statistical generalization and refers to the ability of the researcher to infer conclusions to the population (Gibbert et al., 2008). In an attempt to show that their results had inferential external validity, Aven, Vinnem, & Wiencke, (2007) make the following assertion about decision framework developed using case studies: “the proposed framework is general and applies to all types of risk decision situations” (p. 434).
Theoretical external validity is often called analytical generalization and relates to “he generalization from empirical observations to theory” (Gibbert et al., 2008, p. 1467). Thus what the researchers do is to try to make projections based on their results based on a theoretical analysis. For example, Olsen et al. (2008, p. 11) used to results of their two case studies to generalize to theory as follows:
These results indicate that if we try to isolate the effect of one single mechanism, our understanding will be limited. Incentives, authority and trust are linked to each other in specific ways.
Finally, in reference to Olsen et al. (2005), I do not think that this article dealt with the issues of internal and external validity adequately. First, the authors do not go into a full discussion of validity and how it was achieved. For example, in case study research there are different ways of ensuring validity, including the use of multiple methods (Newman and Benz, 1998). The authors used semi-structured interviews, surveys and participant observations to collect data for their two cases but did not highlight the important of this in supporting validity. Second, as it relates to external validity, the authors only noted:
Concerning external validity or the generalizability of the results, we should note that since we only study two cases, the results should be interpreted with cautiousness. Our findings may be more or less idiosyncratic for the two chosen cases, and we cannot generalize the results to other complex procurement projects or inter-firm cooperation in general (Olsen et al., 2005, p. 5).
However, this gives the idea that case studies cannot have external validity. While case studies do not allow for inferential external validity, they can do very well in providing theoretical external validity (Gibbert et al., 2008) and this was not addressed at all in the article by Olsen et al. (2005). Still, while the researchers did not directly address the fact that their results provided theoretical external validity, the Discussion section of the paper shows that this is exactly what the authors did.
References
Aven, T., Vinnem, J. E., & Wiencke, H. S. (2007). A decision framework for risk management, with application to the offshore oil and gas industry. Reliability Engineering & System Safety, 92(4), 433-448.
Gibbert, M., Ruigrok, W., & Wicki, B. (2008). What passes as a rigorous case study? Strategic Management Journal, 29(13), 1465-1474.
Newman, I., & Benz, C. R. (1998). Qualitative-quantitative research methodology: Exploring the interactive continuum. SIU Press.
Olsen, B. E., Haugland, S. A., Karlsen, E., & Husøy, G. J. (2005). Governance of complex procurements in the oil and gas industry. Journal of Purchasing and Supply Management, 11(1), 1-13.
