The presented paper describes results of a study, comparing personality traits between responder and nonresponder to an online survey. Whereas previous research has shown that personality factors influence internet use and computer­-mediated communication (e.g. Renner, Schotz & Machilek, 2005), there is some evidence for an influence of stable characteristics on survey participation patterns also (e.g. Rogelberg et al., 2003). But especially the results for online surveys appear mixed (Galesic & Bosnjak, 2006).

159 students from an earlier study were invited via E-mail 6 months, after the first study took place, to participate in a short online survey (topic: self-assessment of personality factors, mean duration: 13 minutes, lottery incentives were given). With in the first study setup, people filled out a German version of the NEO-PI-R (Ostendorf & Angleitner, 2004) and the CFT intelligence test (CFT3, Weifi, 1971). Due to small sizes of two subgroups (drop-out and item nonresponder), compari­sons on the personality variables were carried out between responders (complete responder + item nonresponder, n = 92) and nonresponders (unit nonresponder + starting: people, who just filled out the first page (identification code), n = 67). No substantial differences occurred between these two groups on demographic variables as age or gender. However, a multivariate analysis revealed a signifi­cant difference on the domain level of the personality factors (for Neuroticism and Intelligence). According to the hypothesis, differences were found on the sub­facet level for Conscientiousness (C) and Neuroticism (N): Responders scored higher in Competence and Dutifulness, whereas nonresponders scored higher in Vulnerability. Effects are small up to moderate in size, and in total the persona­lity factors are able to predict a significant proportion of variance in participation behaviour within a logistic regression. Com pa ring the personality factor values of the study participants to the German NEO-PI-R norm sample (comparable in age and gender), solely a significant difference for C is confirmable. Possible explanations for the not anticipated effect of intelligence and the postulated, but not proved hypothesis for Openness to experience are discussed. Additionally, the paper evaluates necessary consequences due to systematic nonresponse errors in online surveys.