To this end, this chapter tries to identify the groups that may be at particular risk of suffering from low proficiency in literacy, numeracy and/or problem-solving skills. A lack of information-processing skills could be a major obstacle to full participation in modem societies and could lead to social and economic exclusion and marginalisation. The bars show raw (unadjusted) differences, while the dots represent adjusted differences, estimated after accounting for the impact of other background characteristics.' While the analysis focuses on literacy proficiency, results for numeracy are generally similar. When considering educational attainment, the adjusted differences are generally close to the unadjusted differences, meaning that background characteristics like age, gender or family background have little impact on the strength of the relationship between educational attainment and proficiency. In fact, accounting for differences in educational attainment generally results in a much weaker association between proficiency and other background characteristics.