e initial letter selected. Word-prediction has provided a prosthetic tool for writing output for children with spelling difficulties, so that they can produce written output along with their peers, even without the spelling skills usually required to do so. However, the study of the effectiveness of word-prediction has produced a wide range of results in the literature (Tam, Reid, Naumann & O'Keefe, 2002). Mixed results are attributed to differences in research metho dologies, study populations, computer access devices, word-prediction programmes, user characteristics (Tam et al., 2002), training interventions (Horstmann & Levine, 1992) and the complex interaction between these aspects of word-prediction research. It has been suggested that the conflicting evidence provided by research may be more a function of the nature of instruction and instructional feedback that accompanies the use of wordprediction, than a reflection of the efficacy of the technology itself (Williams, 2002). In addition, caution must also be applied in the use of the quantitative data derived from able-bodied people in word-prediction models that attempt to predict the performance of people with disabilities (Newell, Arnott & Waller, 1992) as different users adopt a wide range of strategies to cope with the individual nature of their disabilities. The specific characteristics or skills of the user impact very significantly on the apparent efficacy of word-prediction use (Koester & Levine, 1998). Factors such as the motor skills of the user, the visual-cognitive demands in word-prediction use and even the motivation of the user to use it (MacArthur, 1999) have received attention in the literature. The use of word-prediction requires an interaction between spelling and sight-reading skills. Although many case studies have reported how word-prediction has aided spelling difficulties, there is little evidence in the literature to attempt to investigate, quantify or correlate the impact of specific spelling skills (or reading skills) on the effectiveness, or lack thereof, of a word-prediction programme to facilitate written work, especially rate enhancement or accuracy improvement. It was the purpose of this research project to investigate the relationship between the use of word-prediction and the ability to spell single words, as well as the role that spelling competence has in a subject’s ability to use a word-prediction programme. Spelling-accuracy support through word completion Word-prediction is a software programme which operates within a word processing programme during the typing process. As soon as a user begins to type a new word, a word list menu is filled with possible words that match the typed letter or letters. If the user selects one of the suggested words (thr1986) for the idea that practice at spelling or producing words improves reading skills, and that seeing the word (reading it) frequently improves the ability to spell it. By using spelling and reading together in the interactive way required by word-prediction, both modalities benefit from each other, as the user is constantly drawing on both his spelling and reading skills in his efforts to produce words. In fact, there is support for a more integrated approach to the teaching of writing and reading based on the strong association between the two skills. Therefore, word-prediction can be seen not only as a prosthetic tool for spelling difficulties, but also as a training aid (Newell, Arnott et al., 1992) that is educationally valid. However, reading is a decoding process and spelling is an encoding process (Allred, 1990) and although there is a high correlation between the performance of individuals in reading and spelling skills, discrepancies between reading and spelling skills may have an important impact on the effectiveness of word-prediction. If a child’s reading is weaker than his spelling, it may seriously limit the chances of wordprediction affecting a speed increase, or even a spelling accuracy increase. On the other hand, if a child with poor spelling skills has stronger reading skills, word-prediction could be expected to have a strong positive influence in improving the child’s spelling speed and accuracy. Speed enhancement through keystroke reduction Word-prediction software offers a 50% theoretical reduction in keystrokes (Anson, 1993). A keystroke is any mouse click or keyboard key event. The average word length in the English language is approximately six characters long but only two to four characters are required on average to type a word with word-prediction software. Keystroke reduction would appear to suggest a corresponding decrease in input time compared to the input time required to type a word in full. However, this has proved not to be the case. Even with an almost 50% reduction in keystrokes, typing with word-prediction often requires as much time to write a message as it does to type the message without word-prediction (Venkatagiri, 1993). The benefit in keystroke savings is usually offset or even exceeded by the cost of making each selection. Scanning the prediction list, eye-gaze shifts (between the keyboard, typing text and prediction list), and the decision-making involved in word selection, can be time consuming. The efficiency of any device-user interaction is measured by two important indicators, namely, speed and accuracy of message generation, i.e. operational competence (Szeto, Allen & Littrell, 1993). Significant gains in spelling accuracy would lose their value if there were significant decreases in speed and increases in effort. Improvements in the quantity of work completed were noted in case studies where students made use of word-prediction (Klund & Novak, 1995; MacArthur, 1999). This was explained more by a decrease in frustration and fatigue, and an increase in motivation that may accompany greater success at writing, than increased speed of typing. The greater the presence of motor difficulties, the greater the positive impact of word-prediction on word acceleration (MacArthur, 1999). If participants do not have motor difficulties, such as in the current study, one would not expect increases in speed of typing when making use of wordprediction software. Additional spelling benefits resulting from word-prediction usage There are other spelling-related benefits accredited to word-prediction, such as helping students to correct errors as they occur, the language development of children, an increase in vocabulary size, improvement in the students’ attitude to writing, improved confidence, independence in writing, increased attention span, increased enjoyment in writing, better presentation of work, improved motivation to write (primarily because of the neater, more readable output the child is producing and the decreased effort required to do so) and fatigue reduction prompted by effort reduction — the cognitive effort in spelling words where there are spelling difficulties can be significant (Gillette & H A concern about the introduction of word-prediction where there are spelling difficulties is that theitself may be difficult to learn and manage, thus placing an additional burden on the writing process (Williams, 2002). No record in the literature has been found of subjects struggling to learn how to use word-prediction. If a subject can use a word processor, does not appear a difficult concept to learn. In some studies it was noted that only a brief introduction to the software and its features was required before the subjects could use the software (Newell, Booth et al., 1992; Williams, 2002). There is sufficient support in the literature to support the benefits of ongoing instruction, and practice, which are considered paramount to the successful usage of a word-prediction Practice at word-prediction appears to have a very significant impact, with users improving significantly as they become familiar with using the & Nov