One of the main reasons researchers investigate experiences of violent behaviour is that such behaviour has various negative consequences for the person or group being victimised.Violence-related negative effects may be expressed in feelings of anxiety, depression, low self-esteem, and loneliness (Duke, Pettingell, McMorris, & Borowsky, 2010). An experience of violence may also involve physical pain and injury or material damage, for example vandalism (Bayh, 1975). Moreover, frequent victimisation by peers at school is associated with poor academic performance (Schwartz, Gorman, Nakamoto, & Toblin, 2005). Violence perpetrated in and around school, including on the Internet, is interpreted as a threat to safety and social cohesion (Chen & Astor, 2011;Finkelhor, Omrod, Turner, & Hamby, 2011;Siu, 2011). Violence-related experiences in and around schools are therefore a major concern in the educational policy of countries such as the United States relationship patterns between personal and other characteristics of secondary school pupils and their motives as a victim, perpetrator, or witness of six types of violent behaviour, in relation to the complementary social roles of other pupils, teachers, other school staff, and pupils' relatives. In the same vein, Mooij (2011b) has examined social interaction patterns between the personal and school characteristics of secondary school teachers and their experience of violence in differentiated ways.Because violence is measured in different areas, in different ways, and within different groups, and because the results are used in different designs, it is somewhat difficult to compare the research findings of multiple studies or to assess their relevance for identifying or reducing the negative effects described above. Michie and Cooke (2006) have summarised the problems involved in violence measurement as: Multidimensionality in assessment; non-empirical ordering of violent acts; inclusion of undiscriminating items; and differential precision of measurement across the range of seriousness. They themselves used the MacArthur Community Violence Screening Instrument (MCVSI) to interview 250 male prisoners between 18 and 40 years of age. They applied Item Response Theory (IRT) and found that the instrument's items were not ordered correctly in terms of the severity of the underlying trait; additional items were required to improve discrimination.Given the diversity of violence concepts and assessment procedures, it is worth looking more closely at IRT. IRT models generally show how the items in a scale function relative to one another and where each item is situated on the continuum of an underlying construct from low to high severity or difficulty (cf. Schafer, 1996). When the items form a unidimensional scale, it is appropriate to combine them in order to reach a total score that can be related to the scores of other variables. IRT may therefore solve some of the problems associated with the measurement of violence. An example is given by Regan, Bartholomew, Kwong, Trinke, an...