APA Dictionary of Psychology

a figure describing the hypothesized relations tested in an analysis of simultaneous linear relationships among measured or manifest variables; the object is to identify the causal relationships or logical ordering among variables. Each measured variable is designated by a box, and latent variables are represented by ovals. Covariances or correlations between exogenous variables and between errors are represented by curved lines with arrowheads at both ends. Paths are represented by straight lines with an arrowhead pointing from the independent variable toward the dependent variable. Associated with each path is either an asterisk or a number. The asterisks indicate free parameters, whose values will be estimated from the data, whereas the numbers indicate fixed parameters, whose values do not change as a function of the data. Also called path model. See also path analysis.