Reading and Writing: An Interdisciplinary Journal 12: 63–97, 2000.
© 2000 Kluwer Academic Publishers. Printed in the Netherlands.
Are nonword and other phonological deﬁcits indicative of a failed
G. BRIAN THOMPSON
& RHONA S. JOHNSTON
Victoria University of Wellington, Wellington, New Zealand;
University of St Andrews,
St Andrews, Scotland
Abstract. Phonological processing problems have been considered critical in explaining
developmental reading disability. Reading disabled children were compared with two matched
reading-level normal control groups on indicators of phonological processing. The reading
disabled children had lower nonword reading performance than the phonics taught controls.
However, performance was equivalent to that of the controls without phonics teaching. There-
fore a nonword reading deﬁcit was not in itself diagnostic of developmental reading disability.
The reading disabled children and the non-phonics control group who exhibited lower non-
word reading did not differ from the phonics taught control group in phoneme awareness,
nor in magnitude of the word regularity effect. Nevertheless, within all groups those children
with higher phonemic awareness skills showed larger word regularity effects and better non-
word reading. Processes involving two sources of knowledge for phonological recoding are
discussed as explanations of these and many previous results on phonological deﬁcits and of
the phonological effects of phonics instruction.
Keywords: Developmental reading disability, Nonword reading, Phonics instruction, Phono-
logical awareness, Phonological deﬁcit, Word regularity effect
Over the past ﬁfteen years most research into developmental disorders of
learning to read have either implicitly or explicitly been carried out within
a dual-route theoretical framework. According to this framework, in skilled
reading of an alphabetic orthography, words may be accessed by either or
both of two routes (Coltheart 1978; Coltheart, Curtis, Atkins & Haller 1993).
There is said to be a direct visual route whereby the meaning or pronunciation
of the word can be accessed without sublexical spelling-to-sound conversion.
This route, which depends on familiarity with the printed word, is said to be
obligatory for words that are irregular in spelling-to-sound correspondences,
such as ‘done’, in which the conversion of the sequence of graphemes into
corresponding sounds would produce a mispronunciation. However, regular
words, e.g. ‘top’, and nonwords, e.g. ‘kug’, may be read by such a grapheme-
to-phoneme conversion (phonological recoding) route. The use of such a