The data gathered were then calculated to obtain the CVR based on Lawshe's formula (Lawshe, 1975). According to Lawshe, with a panel of 40 respondents, the minimum value of CVR needs to be at least 0.29 in order for it to be acceptable. As a result, variables which have CVR values less than 0.29 were not included in final questionnaire. This preliminary study showed that all 16 variables had CVR value greater than 0.29, varying from 0.70–1.00. Thus, it was inferred that all 16 CSFs were strongly valid for this research and they could be included in the final form of a questionnaire.