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 objectives, the fourth objective is thus discussed in a transversal way.Carried on five establishments (two in Wallonia, one in France and two in Quebec), this research is based on a two-phase mixed methodology. The quantitative phase involved three tests conducted on 245 preservice teachers (N = 245). During the second phase, the qualitative one, 32 students (n = 32, selected among the 245 participants) were interviewed, particularly to describe knownstrategies to evaluate information. In addition, we observed practices and strategies mobilized by nine of them (n = 9) to evaluate information from documentaries and discuss it on a social media.The first article illustrates the complexity of critical thinking measurements but demonstrates the psychometric robustness of the French version of the Halpern Critical Thinking Assessment test, a test for scoring critical thinking skills. Furthermore, we postulate that critical thinking self- efficacy, significant predictor of skills, should be considered as a disposition to critical thinking. We have also developed an indicator measuring self-efficacy in terms of metaliteracy. In a second article, we tried to define the best predictors of critical thinking skills scores. A linear model (including country of study, type of training, employment as well as self-efficacy in critical thinking and metaliteracy) is statistically significant although with limited predictive capability. However, strategies and practices described in the third article and observed in real-life context show only minimal differences between used strategies: it seems that students following a vocational training would more likely mobilize metacognitive and self-critical strategies when their counterparts in disciplinary training use more criterion-referenced strategies.The research highlights the positive role of relationship to current and prospective employment of preservice teachers in defining critical thinking skills and dispositions, combined with specific strategies for dealing with information. The results support the increase of preservice teacher training integration into educational practice and suggests the support of career planning to develop critical thinking skills. Strength and limitations of the research are discussed and several recommendations are offered for research project and educational system, in terms of educational policy and school practices.