SEM analyses have used a process called “invariance” (indicating a lack of difference across groups) within the SEM to determine if it was reasonable to combine the sexes in the analyses. However, determining that it is acceptable to combine males and females does not necessarily mean that the effects of LR in the two sexes are the same. Using a recent study as one of several possible examples, in an evaluation of a large sample of adolescents, invariance analyses indicated that males and females were similar enough to combine, even though the LR values were different across sexes, as were some relationships among the items used to measure some of the components of the model [19]. These and other results [e.g., 17, 18] indicated to us that it might be useful to more fully and directly explore potential male/female differences in the LR-based SEMs.
