Socially problematic and violent behaviour of pupils in and around schools is undesirable from pedagogical, social and societal perspectives. The motives underlying violence between different social actors in school may help explain and improve this behaviour. The aim is to investigate the relationship patterns between characteristics of secondary school pupils and their problem social behaviour including the motives they attribute to being a victim, perpetrator or witness of six types of violence, in relation to the complementary social roles of other pupils, teachers, other school staff and pupils' relatives, respectively. Data was collected with the aid of a Dutch nationwide Internet-based survey in secondary schools. A total of 80,770 pupils from 215 school locations completed the questionnaire. Data was checked for reliability, scale homogeneity and representativeness. Pearson correlations show that pupil characteristics indicating educational attainment level (low), feeling at home in the Netherlands (not feeling at home), gender (male) and age (being older) are most important in problem social behaviour and violence motive patterns. Being religious is less relevant; degree of urbanisation is least relevant. The motives attributed most often refer to physical appearance, behaviour, level of school achievement, handicap, being religious, gender, sexual preference and ways of dealing with non-conforming behaviour or punishments. Social interactions between pupils and between pupils and teachers are generally most important for eliciting violence-related motives, followed by interactions between pupils and pupils' relatives. The results are comparable with those from printed questionnaires in nationwide research, which supports the validity of the Internet-based survey. It is concluded that the substantive results provide a more complete, thorough and systematic picture of social discrimination and motive aspects than has hitherto been customary. The resulting indicators can be used in Internet-based feedback procedure cycles to inform school policy about evidence-based results comparing the school's own pupils, teachers, educational support staff and management to national benchmarks so as to support efforts to improve social safety in and around school. (Contains 10 tables.)