Restricted to five Spanish public universities, this paper examines knowledge about information literacy competencies--that is, the objective dimension--among a population of social sciences students, as well as two subjective dimensions: students' belief in the importance of information literacy, hereafter called "belief-in-importance", and their perceptions of self-efficacy, their confidence in their ability to succeed. Common characteristics and substantial differences among students in different degree programs are also investigated. Understanding the factors underlying the one objective and two subjective dimensions and their mutual relationships was a major objective. Finally, common competencies in the three dimensions are provided.