EDUCATION FOR LIFE AND WORK - Hewlett Foundation

Education for Life and Work: Developing Transferable Knowledge and Skills in the 21st Century
26 EDUCATION FOR LIFE AND WORK
is poor. In psychometric modeling, constructs viewed as separate from their
measures are referred to as latent (as opposed to observed or measured)
variables. There are two types of latent variables: reflective latent variables
and formative latent variables (see Figure 2-1).
Following a concept proposed by Spearman (1904, 1927), a reflective
latent variable is identified based on correlations among scores from a
set of tasks. Differential psychologists discover reflective latent variables
using factor analysis and related methods to identify the patterns of correlations
among a set of “indicator variables”—scores on tests and rating
instruments used to measure cognitive and noncognitive competencies. A
reflective latent variable—such as general cognitive ability or one of the
“big five” personality factors (McCrae and Costa, 1987)—is thought to
reflect the essence of, or the commonality among, the various competencies
measured. In psychometric modeling, a reflective latent variable (also called
a factor because it is discovered through factor analysis) is said to cause
the relationships among the set of indicator variables (see Figure 2-1). For
example, extraversion, a personality factor, is thought to cause relatively
high scores on instruments measuring warmth, gregariousness, and assertiveness.
Within a reflective latent variable, the importance or weighting of
an individual indicator variable is a function of how highly that particular
indicator variable correlates with other indicator variables for the reflective
latent variable (Bollen and Lennox, 1991).
Reflective
Formative
FIGURE 2-1 Casual structures in reflective and formative latent variables.
SOURCE: Stenner, Burdick, and Stone (2008). Reprinted with permission.
Figure 2-1
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