TPC Journal-Vol 11-Issue-3 - FULL ISSUE

268 The Professional Counselor | Volume 11, Issue 3 2013; NBCC, 2016; Neukrug & Fawcett, 2015). The extant literature includes a series of articles on factor analysis, including exploratory factor analysis (EFA; Watson, 2017), confirmatory factor analysis (CFA; Lewis, 2017), higher-order CFA (Credé & Harms, 2015), and multiple-group CFA (Dimitrov, 2010). However, reading several articles on factor analysis is likely to overwhelm professional counselors who are looking for a desk reference and/or comparative guidelines to evaluate the validity evidence of scores on instruments before administering them to clients. To these ends, professional counselors need a single resource (“one-stop shop”) that provides a brief and practical overview of factor analysis. The primary purpose of this manuscript is to provide an overview for the layperson of the major types and extensions of factor analysis that counselors can use as a desk reference. Construct Validity and Internal Structure Construct validity, the degree to which a test measures its intended theoretical trait, is a foundation of assessment literacy for demonstrating validity evidence of test scores (Bandalos & Finney, 2019). Internal structure validity, more specifically, is an essential aspect of construct validity and assessment literacy. Internal structure validity is vital for determining the extent to which items on a test combine to represent the construct of measurement (Bandalos & Finney, 2019). Factor analysis is a key method for testing the internal structure of scores on instruments in professional counseling as well as in social sciences research in general (Bandalos & Finney, 2019; Kalkbrenner, 2021b; Mvududu & Sink, 2013). In the following sections, I will provide a practical overview of the two primary methodologies of factor analysis (EFA and CFA) as well as the two main extensions of CFA (higher-order CFA and multiplegroup CFA). These factor analytic techniques are particularly important elements of assessment literacy for professional counselors, as they are among the most common psychometric analyses used to validate scores on psychological screening tools (Kalkbrenner, 2021b). Readers might find it helpful to refer to Figure 1 before reading further to become familiar with some common psychometric terms that are discussed in this article and terms that also tend to appear in the measurement literature. Figure 1 Technical and Layperson’s Definitions of Common Psychometric Terms Psychometric Term Technical Definition Layperson’s Definition Confirmatory Factor Analysis Theory-testing strategy for appraising the internal structure of a hypothesized factor solution with a new sample. A statistical test for evaluating the internal structure of scores on an existing instrument when it is given to a new sample. Construct Validity A type of validity evidence involving the extent to which test scores accurately appraise the intended latent variable. A form of validity for determining if scores on a test collectively measure what the test developers claim it measures. Dimensionality See internal structure. See internal structure. Exploratory Factor Analysis Psychometric test for reducing an inter-item correlation matrix and uncovering the internal structure of scores on a new or previously untested instrument. A psychometric test for uncovering the internal structure of scores on a new test. Factor(s) A collection of test items that cluster together based on conceptually related dimensions to form a composite latent variable. Factors are also referred to as “subscales.” The overall latent variable that is created by a series of test items that are grouped together because they share a common meaning. Factor Analysis Multivariate statistical analyses for uncovering and confirming the internal structure of test scores. A series of tests for evaluating the internal structure of test scores.