Evaluation of the Psychometric Properties of the Internet Addiction Test (IAT) in a Sample of Cypriot High School Students: The Rasch Measurement Perspective

As Greek Cypriot senior high school teachers, the researchers believe that instruments assessing Internet addiction should be developed and validated for use wherever there are adolescents (the most at-risk population) and Internet access. The purpose of the study was to evaluate the psychometric properties of the Internet Addiction Test (IAT). A sample of 604 randomly selected high school students from five high schools in Limassol, Cyprus participated in the study. The Rasch Rating Scale Model was used for the analyses of the data collected. Results suggested the modification of the IAT in two ways. First, the 5-point rating scale was replaced by a 3-point scale, which was found to be optimal in the pilot study. Second, item 8 was replaced by a self-rating item because it was found to be identical to item 6 both statistically and semantically. The respondents’ reliability was satisfactory (0.86) and item reliability very high (0.99). All 20 items were sufficiently spread out and describe distinct levels along the variable and do define a linear continuum of increasing difficulty. All the evidence collected supports the unidimensionality and the high degree of construct validity of the scale. Finally four recommendations for the modification of the scale and future research are proposed.