Introductory And Intermediate Growth Models - Mplus

Quadratic growth modelSpecifying Time Scores ForQuadratic Growth Models2y ti = η 0i + η 1i x t + η 2i x t + ε ti ory2ti = η0i+ η1i⋅(xt− c ) + η2i⋅(xt− c )where c is a centering constant, e.g.• Need three latent variables to describe a quadratic growthmodel: Intercept, linear slope, quadratic slopexOutcome1 2 3 4Time• Linear slope time scores: 0 1 2 3 or 0 .1 .2 .3• Quadratic slope time scores: 0 1 4 9 or 0 .01 .04 .09115Specifying Time Scores For Non-LinearGrowth Models With Fixed Time ScoresNon-Linear Growth Models with Fixed Time scores• Need two latent variables to describe a non-linear growthmodel: Intercept and slopeGrowth model with a logarithmic growth curve--ln(t)Outcome1 2 3 4TimeTime scores: 0 0.69 1.10 1.3911658