Diversity of functional illiterate cases: Results from a multiple-single case study

Abstract

Functional illiteracy characterizes people who, despite formal education, do not possess the basic literacy skills to deal with everyday life requirements. Although a few studies have shown the heterogeneity of functional illiteracy, empirical research to differentiate these people at the individual level of more basic skills is lacking. The goal of this study is to assess the linguistic, cognitive, and numerical skills of functional illiterates: first, by comparing cases to each other; second, by comparing them to a literate control group across these domains. For this purpose, a multiple single-case methodology commonly used in neuropsychological case studies was employed, in the field of educational research. The results revealed heterogeneity in one of the literacy tests (leo.), in lexical access, in auditory story comprehension, and in spatial representation of numbers, while the pattern of results indicated more homogeneity in the other literacy test (ELFE 1-6), in non-verbal IQ, in phonological processing, in auditory grammatical comprehension, in arithmetic, in magnitude processing, and in place-value integration. Moreover, the multiple case design showed that the presented functionally illiterates perform significantly worse than the literate group on most of the measures. Further research should consider using differential diagnostics of literacy, linguistic and numerical abilities.