3.4. The TpB model to explain the intention of engaging in premarital sex
Multi-sample structural equation modeling (MSEM) was carried out to examine gender differences in the TpB model of intention to engage in sex. As the first step, each gender group model fitting was examined. The models showed very poor fit indices in both gender groups (see Table 2, Model 1). Thus, Model 2 was examined to determine whether it was appropriate as a baseline model (See Table 2). However, Model 2, which had an error covariance between mothers’ norms and fathers’, was also inappropriate to act as a baseline and one of the free parameters (peer norm under the construct of perceived norms in the model of premarital sex) had a negligible error variance. Thus, the error variance of the peer norm was fixed as 0.0 in the Model 3. Then, the new model (Model 3) became the baseline model in this study (See Table 2).