This collective case study focuses on critical thinking and literacies (informational, digital, media, etc.), understood with the concept of metaliteracy, for students beginning higher education and destined to be secondary school history teachers. The objective is to present a portrait of critical thinking and metaliteracy among these preservice teachers from the French-speaking world, in an era of social networks. The background of the research includes an increasing number of fake-news and conspiracy theories with proven socio-political and health impacts in election or pandemic contexts. We studied students from Wallonia (Belgium), France and Québec (Canada), especially because of these nation’s approach to train preservice teachers (vocational training vs disciplinary training). To conduct this project, several specific objectives were formulated. These were: i) to analyse the metric quality of French-version tests quantifying critical thinking skills and dispositions as well as metaliteracy self-efficacy; ii) to describe preservice teacher scores in critical thinking, particularly in respect with environmental (type of training, country of study, employment) and personal (self-efficacy in critical thinking and metaliteracy, belief in the likelihood of becoming teacher) factors; iii) to discriminate between critical thinking and metaliteracy strategies used by preservice teacher in Wallonia, France and Quebec when navigating in a social media (here Facebook) used as digital personal learning environment (PLE) with respect to the type of training and some environmental (perception of the educational and digital environment) and personal (self-efficacy) factors. A last specific objective, transversal to the first three, consisted in iv) engaging socio-cultural factors and taking into account the educational path, in perceptions and practices related to metaliteracy and critical thinking, in the social web era. This thesis follows a presentation by article; each one of them is related to one of the first three ...