c. Using the concepts of setting parameters to be the same from the multi-group section of the chapter, constrain the factor loadings of the Locus factor to be the same over time. That is, constrain the loadings for luck8, luck10, and luck12 to be the same, constrain the loadings for stops8, stops10, and stops12 to be the same, and so on. Do the same for the Ach factor loadings. Using a criterion of ΔCFI larger than an absolute value of .01, decide whether these model modifications are reasonable. This is a type of factor invariance; it and the ΔCFI criterion will be discussed in more detail in Chapter 19.