Oral vocabulary and learning to read morphologically complex words: mechanisms of influence

It is well-established that there is a causal relationship between oral vocabulary and written word reading. However, it is not clear in what ways oral vocabulary facilitates reading and how morphological information interacts with this facilitation. This thesis aims to examine a cognitive mechanism recently proposed to explain the facilitatory role of oral vocabulary on reading and the potential role of morphology on the use of this cognitive mechanism. Chapter I consists of a literature review in order to present an overview of the relevant evidence for oral vocabulary being causally associated with reading. Possible cognitive mechanisms are discussed. One such mechanism, the orthographic skeleton hypothesis, which is tested in the present study, is described in detail. The chapter further overviews the evidence on how readers use their morphological knowledge while reading and how orthographic skeletons could be linked with reading morphologically complex words. The type of morphological complexity (inflection and derivation) as well as their relevance to skeletons and reading in general are discussed. Chapter II is an empirical investigation of the skeleton hypothesis for two types of morphologically complex novel words (inflected and derived) using a novel oral word learning paradigm, followed by one of two written tasks: self-paced reading or lexical recognition. The first aim was to test whether orthographic skeletons were formed for the stems (i.e., bases) of morphologically complex words upon oral training of these complex words, whereas the second aim was to investigate whether orthographic skeletons were formed independently of affix type. The main findings relate to lexical recognition and indicated that orthographic skeletons are built for the stems of complex words, and this is not dependent on the type of affix. Interactions between phonology, orthography and morphology during the process of reading new words are discussed.