“…Who: Scrum Team, PO, and SM. How: many ways were chosen by the teams and organization to conduct retrospective meetings, including regular retrospective [2,31,62], common retrospectives with all the team [13,17,18,69,70,94], retrospectives every second [56,70,94] or third sprint [57], and even the absence of the practice [56]. In Bass's case study [31], the teams just conducted a regular Scrum Retrospective by the end of each sprint to understand what had been wrong, what was good, and what could be improved.…”