Latent Interaction (and Moderation) Analysis in Structural Equation Models (SEM) // Estimation of interaction (i.e., moderation) effects between latent variables in structural equation models (SEM). The supported methods are: The constrained approach (Algina Moulder, 2001). The unconstrained approach (Marsh et al., 2004). The residual centering approach (Little et al., 2006). The double centering approach (Lin et al., 2010). The latent moderated structural equations (LMS) approach (Klein Moosbrugger, 2000). The quasi-maximum likelihood (QML) approach (Klein Muthn, 2007) The constrained- unconstrained, residual- and double centering- approaches are estimated via 'lavaan' (Rosseel, 2012), whilst the LMS- and QML- approaches are estimated via 'modsem' it self. Alternatively model can be estimated via 'Mplus' (Muthn Muthn, 1998-2017). References: Algina, J., Moulder, B. C. (2001). doi:10.1207/S15328007SEM0801_3. "A note on estimating the Jreskog-Yang model for latent variable interaction using 'LISREL' 8.3." Klein, A., Moosbrugger, H. (2000). doi:10.1007/BF02296338. "Maximum likelihood estimation of latent interaction effects with the LMS method." Klein, A. G., Muthn, B. O. (2007). doi:10.1080/00273170701710205. "Quasi- maximum likelihood estimation of structural equation models with multiple interaction and quadratic effects." Lin, G. C., Wen, Z., Marsh, H. W., Lin, H. S. (2010). doi:10.1080/10705511.2010.488999. "Structural equation models of latent interactions: Clarification of orthogonalizing and double-mean-centering strategies." Little, T. D., Bovaird, J. A., Widaman, K. F. (2006). doi:10.1207/s15328007sem1304_1. "On the merits of orthogonalizing powered and product terms: Implications for modeling interactions among latent variables." Marsh, H. W., Wen, Z., Hau, K. T. (2004). doi:10.1037/1082-989X.9.3.275. "Structural equation models of latent interactions: evaluation of alternative estimation strategies and indicator construction." Muthn, L.K. and Muthn, B.O. (1998-2017). "'Mplus' Users Guide. Eighth Edition." https://www.statmodel.com/. Rosseel Y (2012). doi:10.18637/jss.v048.i02. "'lavaan': An R Package for Structural Equation Modeling."