instrument is to check the validity of each item that making up a latent variable. An item is considered valid if its coefficient correlation over the critical value equal to 0.3[20]. Examination of alpha coefficients shows seven out from 8 coefficients have values greater than 0.7 as a critical value. Only one latent, norms and beliefs, has value less than this critical value. However, for explanatory research, Cronbach’s alpha less than 0.7 but greater than 0.6 is acceptable [19]. From this viewpoint, all of latents in the model have sufficient internal consistency. In addition, examination of corrected total-item correlation for each of items in the model shows all items have total-item correlation above the critical value and are valid to represent their latent variable. Furthermore, we conclude that the questionnaire used in the research have sufficient quality