validity, reliability and factor analysis of compulsive internet use scale in students internet users of isfahan’s universities

introduction: compulsive internet use scale (cius) is a newest and prestigious questionnaire in the diagnosis of internet addiction .the goals of this study was to investigate the reliability and validity (psychometric properties) of persian version of cius in internet users of isfahan's universities. methods: in this descriptive and cross- sectional research  400 isfahan university students were enrolled by quota sampling method. studied population completed demographic questionnaire, persian version ofcius, internet addiction test (iat) and young diagnostic questionnaire (ydq).finally, to determine the cut off point, all studied subjects were interviewed clinically based on diagnostic criteria for internet addiction (dsm- iv- tr). after collecting and scoring the questionnaires, the psychometric  features of the questionnaire analyzed using factor analysis, discriminative validity, internal consistency (cronbach’s alpha), split half, and roc curve by spss15 software. results: factor analysis revealed three factors for cius. it has good internal consistency (cronbach’s alpha = 0.89), split half (r = 0.89), discriminative validity (r = 0.68) and concurrent validity (0.78,0.81).the best cut off point for this questionnaire (cius) was 37. conclusion: cius has acceptable psychometric properties and this is a valid and reliable instrument that may be used in research on internet addiction.