Development and psychometric properties of the Polish basic version of the SDM questionnaire for measuring bullying

Aim. This article presents the construction, validation and psychometric properties of the Polish basic version of a workplace bullying questionnaire (called the SDM questionnaire). Method. The tool was developed in phases, with reference to the international bullying literature and Polish socio-organizational background. The study from 2005/2006 (N = 347) established the structure of the scales' reliability, while the questionnaire's convergent validity was tested in 2018 (N = 500). Among the main statistical methods used were exploratory factor analyses, estimation of internal consistency with Cronbach's α and correlations analyses. Results. The main version of the SDM questionnaire comprises two consistent, correlating scales: the main behavioural scale (SDM-IDM scale, 43 items; Cronbach's α = 0.96) used for diagnosing exposure to bullying behaviours; and an auxiliary emotional-cognitive scale (SDM-ODC scale, 21 items; Cronbach's α = 0.97), which completes the psychological picture of bullying interaction. Each of these scales may be divided into three, more specific, subscales. All of the SDM questionnaire scales positively correlate with the negative acts questionnaire - revised and with three self-report measures of job stressors. Conclusion. The SDM questionnaire is an accurate and reliable psychometric tool for measuring workplace bullying in Polish conditions.