Introduction: Social media are increasingly popular and emerging as important information sources. The study investigates how users' sex and problem-solving style affect their use and evaluation of social media in two contexts. Method: A Web survey including the problem solving inventory (problem solving inventory) was used to collect data. Over 1,000 undergraduates in the United States participated. Analysis: For each context, two-way ANOVAs were conducted with sex and problem solving inventory score as independent variables and the frequency of using different social media platforms and the frequency of taking different evaluative actions as dependent variables. Results: In academic contexts, significant sex effects were found in the use of wikis, blogs and internet forums. Significant effects of problem-solving style were found in the use of social networking sites, user reviews, blogs and microblogs. An interaction between sex and problem-solving style was found in the use of social networking sites and microblogs. In everyday life contexts, sex effects were found. Males used wikis and internet forums whereas females used social networking sites and microblogs frequently. As for problem-solving styles, ineffective problem-solvers used internet forums frequently. Regarding the use of evaluation strategies, females with effective problem-solving styles checked other users' reactions frequently while males with ineffective style did so in academic contexts. In everyday contexts, effective problem-solvers used most of the evaluation strategies frequently. Conclusions: Social media use and evaluation behaviours varied depending on contexts. sex effects remained significant when problem-solving style has been taken into account. Findings suggest that effects of sex on information behaviour may need to be examined along with other psychological and sociocultural factors. [This paper was published in: "Proceedings of ISIC: The Behaviour Conference" (Leeds, England, Sep 2-5, 2014), Part 2, Paper isic24.]