Adaptive learning technologies (ALTs) provide teachers with student data in teacher dashboards (TDs). However, there is substantial variation in dashboard use among teachers, and many find it difficult to draw conclusions based on student data. Teachers' skills, knowledge, and contextual conditions are believed to be essential in effective dashboard use. In this study, 26 primary school teachers using dashboards daily were interviewed about their perspectives on the skills, knowledge, and contextual conditions needed to facilitate dashboard use. Results indicated that teachers require a combination of skills, knowledge, and contextual conditions to make well-informed decisions while using a dashboard, emphasizing data literacy skills and pedagogical knowledge. In addition, teachers addressed other competencies, such as skills and knowledge related to the ALT curriculum and general computer proficiency. Also, contextual conditions at the school and technology level were found to be necessary. Based on these results, we propose various factors to explain teacher dashboard use.