ABSTRACT
Several techniques have been developed to assess the comparability of concepts. Two of the most common techniques are multiple-group con-rmatory factor analysis (MGCFA; Bollen, 1989; Jöreskog, 1971) and means and covariance structure analysis (MACS; Sörbom, 1974, 1978). ese techniques can test for congural, metric, and scalar invariance (see e.g., Chapters 2-4, 7, and 9 in this book). Congural invariance indicates that the same indicators measure the same theoretical constructs across groups or time points. Metric invariance is more restrictive; it indicates that respondents interpret the intervals on the response scale in a similar way across groups. Metric invariance with continuous latent variables indicators means that the loadings of the indicators on the factors are equal across groups and/or time points. is implies that the constructs tap the same content across the groups. e most restrictive level of invariance with continuous latent variables indicators, scalar invariance, requires that the intercepts of each item be the same across groups and/or time points. is means that respondents in dierent contexts use the same scale origin. As other chapters in this book explain (e.g., Chapters 4, 5, 7, and 9), metric invariance permits the comparison of correlates across countries and/or time. Scalar invariance also permits the comparison of latent variable means. e scalar invariance model constrains the means of the latent variables to zero in one group (referred to as the reference group) and estimates them in the other groups.
