Please click on this post to open a graphic representation of SO-MG-LCM.
Figure 1. Second Order Latent Curve Models with parallel indicators (i.e., residual variances of observed indicators are equal within the same latent variable: ε1 within η1and ε2 within η2). All the intercepts of the observed indicators (Y) and endogenous latent variables (η) are fixed to 0 (not reported in figure). In model A, the residual variances of η1 and η2 (ζ1 and ζ2, respectively) are freely estimated, whereas in Model B they are fixed to 0. ξ1, intercept; ξ2, slope; κ1, mean of intercept; κ2, mean of slope; ϕ1, variance of intercept; ϕ2, variance of slope; ϕ12, covariance between intercept and slope; η1, latent variable at T1; η2, latent variable at T2; Y, observed indicator of η; ε, residual variance/covariance of observed indicators.