The Scale of Excessive Use of Social Networking Sites – the psychometric characteristics and validity of a proposed tool

Introduction: The paper describes the process of developing a tool to measure social networking site addiction among adolescents, that is the Scale of Excessive Use of Social Networking Sites (SEUS). Material and methods: Three studies (Study 1, N = Study 2, N = 351; Study 3, N = 1054) were performed to establish psychometric properties, construct and criterion validity of SEUS Słowa among Polish high school students. Two different versions of SEUS were developed (48- and 30-item). Their results were correlated with the Bergen Facebook Addiction Scale (BFAS) and standardised questionnaires for measuring psychological variables. Results: SEUS construct validity was checked with Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) procedures. The long 48-item version was reduced to 14 items on which SEUS-14 is based. The final one-factor solution explained 57.7% of variance. The reliability measured with Cronbach’s α is very good. SEUS-14 correlates with BFAS and psychological measures of personality traits, narcissism, self-esteem and Behavioural Activation System, which confirms the scale criterion validity. Discussion: The presented study findings are consistent with the results of other research on Facebook or internet addiction. Regarding the construct validity, one-factor solution turned out to be the best while correlation analysis confirmed SEUS criterion validity. Conclusions: SEUS-14 has demonstrated good psychometric properties in a national sample of Polish adolescents. The measure, treated as a screening tool, can be used for scientific purpose though further studies on the broader use of the scale are necessary.