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

  • Réka VágvölgyiEmail author
  • Luise Marie Rohland
  • Moritz Sahlender
  • Thomas Dresler
  • Josef Schrader
  • Hans-Christoph Nuerk


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.


Adult education Functional illiteracy Linguistic skills Mathematical skills Single case methodology 

Diversität funktionaler Analphabeten: Ergebnisse einer multiplen Fallstudie


Funktionale Analphabeten gelten als eine heterogene Gruppe von Personen, deren Lese- und Schreibfähigkeiten trotz Schulbildung für alltägliche Anforderungen nicht ausreichen. Eine empirisch fundierte Differenzierung auf Basis grundlegender Kompetenzen existiert bisher nicht. Um die linguistischen, kognitiven und numerischen Kompetenzen funktionaler Analphabeten zu untersuchen, wurde eine multiple Fallstudie durchgeführt. Dafür wurden funktional analphabetische Personen miteinander, sowie mit einer Stichprobe literalisierter Personen verglichen. Die Ergebnisse zeigen Heterogenität in einem der Alphabetisierungstests (leo.), im lexikalischen Zugriff und in der räumlichen Zahlenrepräsentation. Homogenere Muster wurden bezüglich des anderen Alphabetisierungstest (ELFE 1-6), des nonverbalen IQ, der phonologischen Verarbeitung, des grammatikalischen Hörverständnis, der Arithmetik, der Größenverarbeitung und der Stellenwertsintegration gefunden. Funktionale Analphabeten schnitten auf den meisten Skalen schlechter ab als die literalisierte Gruppe. Zukünftige Forschung sollte die differenzielle Diagnostik von Literalität, sprachlichen und numerischen Kompetenzen berücksichtigen.


Einzelfallstudie Erwachsenenbildung Funktionaler Analphabetismus Linguistische Kompetenzen Mathematische Kompetenzen 



We would like to thank Bruno Fimm for providing us with the Go/NoGo task of the TAP 2.3 and Urszula Mihulowicz for her help with analyzing the data. Finally, we thank Julianne Skinner and Zoë-Lauren Kirste for the proofreading of the manuscript.


This research (“Basic Foundations of Functional Illiteracy”) is funded by the LEAD Graduate School & Research Network [GSC1028], a project of the Excellence Initiative of the German federal and state governments and by the German Institute for Adult Education—Leibniz Centre for Lifelong Learning e. V.


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Copyright information

© The Editors of the Journal 2019

Authors and Affiliations

  • Réka Vágvölgyi
    • 1
    Email author
  • Luise Marie Rohland
    • 2
  • Moritz Sahlender
    • 3
  • Thomas Dresler
    • 1
    • 4
  • Josef Schrader
    • 1
    • 3
    • 5
  • Hans-Christoph Nuerk
    • 1
    • 6
    • 7
  1. 1.LEAD Graduate School & Research NetworkUniversity of TuebingenTuebingenGermany
  2. 2.Institut de PsychologieUniversité Paris DescartesBoulogne-Billancourt CedexFrance
  3. 3.German Institute for Adult Education – Leibniz Centre for Lifelong Learning (Deutsches Institut für Erwachsenenbildung – Leibniz-Zentrum für Lebenslanges Lernen e. V.)BonnGermany
  4. 4.Department of Psychiatry and PsychotherapyUniversity Hospital TuebingenTuebingenGermany
  5. 5.Department of EducationUniversity of TuebingenTuebingenGermany
  6. 6.Department of PsychologyUniversity of TuebingenTuebingenGermany
  7. 7.Leibniz-Institut für WissensmedienTuebingenGermany

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