**7. Study design and methodology**

A mixed-methods longitudinal research methodology with a qualitative focus was undertaken. The research design involved a 2 phased approach to the study- whereby data would be gathered from the same participants on two occasions; Phase 1 of data collection was designed to take place while schools were closed in June 2020 and it was intended that Phase 2 of data collection would be undertaken when schools re-opened. Schools re-opened in September 2020 and the data for phase 2 was collected in December 2020. Both phases of data collection involved a semi-structured interview, whereby participants could reflect on their experiences of education and schooling since schools were closed on March 12th 2020. The impact of this experience on personal well-being was the key focus of the interview. In the interview in phase 2 the focus again was on participant well-being, involving reflection on personal well-being since return to school. Prior to completion of the interviews in both phases of data collection, participants were asked to complete two short questionnaires; The Emotion Regulation Questionnaire (ERQ ) [28] and the Copenhagen Burnout Inventory adapted for teachers (CBI) [32]. These measures were intended to assess the impact of the pandemic on the teachers' and principals' perceptions of burnout and emotional regulation. Details of phase 1 and 2 of data collection are summarised in **Figure 1** below.
