Let me explain: An infant with a high VAS is usually good at word-guessing because a high VAS allows him to develop sight words very early. However…that initial success increases the risk that he will then come to depend on those sight words and may therefore neglect the development of phonic skills.
This is why VAS Theory stresses the need for teachers in infant schools to regard the range of teaching strategies (phonics, guessing from word-shape, predicting from sentence meaning etc) as being COMPETITIVE rather than cooperative strategies. If you ‘teach everything’ the child may simply choose the reading strategy that suits him best at the moment but that strategy may not equip him for the increasing complexities of language later on.
The high VAS child’s problems may not be apparent until about the age of 10 when he finds that his lack of phonics has undermined his ability to read the increasing number of long words, particularly if they are unfamiliar. Spelling may also suffer.