Developing a Validity Argument Through Abductive Reasoning with an Empirical Demonstration of the Latent Class Analysis

Abstract

This article proposes and demonstrates a methodology for test score validation through abductive reasoning. It describes how abductive reasoning can be utilized in support of the claims made about test score validity. This methodology is demonstrated with a real data example of the Canadian English Language Proficiency Index Program (CELPIP)-General test—a program assessing functional English language ability in the community and workplace. Abductive reasoning seeks the enabling conditions through which a claim about a person's ability makes sense. For example, it makes sense that a person has strong functional language proficiency if he or she has been regularly using English to write emails and meet with colleagues at work. A valid test score should be affected by the extent of a person's engagement with such enabling conditions. Empirical evidence that warrants such an abductively reasoned claim is illustrated through a latent class analysis within a structural equation model. Evidence is examined to investigate whether certain classes of test takers who have been differentially engaging in the enabling conditions do, in fact, predict a person's CELPIP-General performance. The steps of the methodology are summarized in the closing section.

Keywords:

• abductive reasoning
• validity argument
• validity
• validation
• latent class analysis
• CELPIP-General
• interpretation use argument (IUA)

Notes

On the one hand, an explanatory approach (Zumbo, 2007) can make stronger claims than an argument-based approach as the explanation can be shown to be a strong, perhaps best possible, explanation for the phenomena under inspection. Meanwhile, the strength of construct validation is that it demands a comprehensive characterization of the construct along with multiple lines of evidence supporting the validity claims. On the other hand, an argument-based approach seeks evidence that may support an interpretation about how scores are used. The study presented herein offers one line of evidence, that is, one warrant, toward a validity argument, rather than claiming to be a comprehensive justification of score use or the best possible explanation for test taker performance.

Asparouhov and Muthén's (2013) model includes three steps, but the current study only involved two (the step for including auxiliary variables was irrelevant to the current study).