Skip to main content

From Subtypes to Taxons: Identifying Distinctive Profiles of Reading Development in Children

  • Chapter
  • 1283 Accesses

Part of the Literacy Studies book series (LITS,volume 16)

Abstract

The longstanding debate between dimensional and categorical approaches to reading difficulties has recently been rekindled by new empirical evidence and developments in theory. At the heart of the categorical perspective is the tenet that dyslexia is a taxon, a grouping of cases that can account for both intra-group similarities and inter-group differences. As developmental dyslexia is characterized by a diverse constellation of symptoms with multiple underlying risk and protective factors, the key question in dyslexia research has shifted from “What is dyslexia?” to “How many taxons or subtypes of dyslexia are there?” The primary objective of this chapter is to consider methods that can be used to objectively define these groupings, starting with the current practice of defining subtypes of readers using normative scores with pragmatically dened cut-offs, the “Quadrant Analysis” approach, and progressing towards more theoretically sound and statistically rigorous procedures. We review and test several candidate approaches that can be readily adapted to realistic conditions that are problematic for Quadrant Analysis. Specifically we propose a method that can be used to identify subgroups in the bivariate case when the two indicator variables are correlated. We conclude by evaluating the strengths and weaknesses of this and other methods and include implications for their future application toward identifying and validating putative dyslexia taxons.

Keywords

  • Dyslexia
  • Subtypes
  • Orthography
  • Phonology
  • Taxon
  • Development
  • Reading
  • Statistical modelling

This is a preview of subscription content, access via your institution.

Buying options

Chapter
USD   29.95
Price excludes VAT (USA)
  • DOI: 10.1007/978-3-319-90805-2_11
  • Chapter length: 21 pages
  • Instant PDF download
  • Readable on all devices
  • Own it forever
  • Exclusive offer for individuals only
  • Tax calculation will be finalised during checkout
eBook
USD   109.00
Price excludes VAT (USA)
  • ISBN: 978-3-319-90805-2
  • Instant PDF download
  • Readable on all devices
  • Own it forever
  • Exclusive offer for individuals only
  • Tax calculation will be finalised during checkout
Softcover Book
USD   139.99
Price excludes VAT (USA)
Hardcover Book
USD   179.99
Price excludes VAT (USA)
Fig. 12.1
Fig. 12.2
Fig. 12.3
Fig. 12.4

Notes

  1. 1.

    Actually 0.6745 is the 25th percentile so perhaps not as arbitrary as it first appears.

  2. 2.

    The multiplication rule, p(A ∩ B) = p(A) ⋅ p(BA) which is p(BA) = p(B) when A and B are independent.

References

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Adrian P. Burgess .

Editor information

Editors and Affiliations

Rights and permissions

Reprints and Permissions

Copyright information

© 2018 Springer International Publishing AG, part of Springer Nature

About this chapter

Cite this chapter

Burgess, A., Witton, C., Shapiro, L., Talcott, J. (2018). From Subtypes to Taxons: Identifying Distinctive Profiles of Reading Development in Children. In: Lachmann, T., Weis, T. (eds) Reading and Dyslexia. Literacy Studies, vol 16. Springer, Cham. https://doi.org/10.1007/978-3-319-90805-2_11

Download citation

  • DOI: https://doi.org/10.1007/978-3-319-90805-2_11

  • Publisher Name: Springer, Cham

  • Print ISBN: 978-3-319-90804-5

  • Online ISBN: 978-3-319-90805-2

  • eBook Packages: EducationEducation (R0)