vaslogo Visual Attention Span

VAS (Visual Attention Span) testing can only be accomplished using the computer. Knowing a child's VAS level is critical in cases where whole word teaching methods are being followed. The link below provides access to the free 0n-Line programme that tests both VAS levels and Basic Reading Skills. This programme also provides an explanation of VAS Theory so that educators can gain an understanding of the reason why children with low VAS levels become poor readers - and most importantly - how this failure can be avoided.

VAS Theory was developed by Byron Harrison and the author Jeanie Clyde. Byron supplied data for thousands of cases, I supplied the teacher's perspective; together we developed VAS Theory which predicts which children will be inaccurate in whole word guessing and explains the nature of their inaccuracy.

It started with Byron plotting the movements of eyes across line drawings of houses and noting that the children were paying most attention to those parts adjacent to spaces, the chimney sticking up into space and the end of eaves sticking out into space.

When we applied this technology to words, we found the same principles applied: children were paying attention to those lower case letters with limbs sticking up (or hanging down) into space plus the two letters at the ends of small words.

Take the word
'magnet' for example. The letters with limbs hanging down or intruding up into space are the 'g' and the 't'. The letters at the ends are 'm' and 't'. He called these letters the 'high visibility letters'. In the word 'magnet' the high visibility letters are therefore m-g--t.

We then noticed that some children seemed to be able to recall more of these high visibility letters than other children and that the higher the number of letters that could be held in memory, the better the chances of guessing a word correctly.

Take the word 'magnet' again. The high visibilty letters are m-g--t. If the child could hold all three letters in memory, that visual pattern looked like
'maggot' , 'midget' , 'magnet' or 'might'. Some children were then often able to guess which one was correct from the other words in the sentence.

However when other children looked at the word 'magnet' they made more bizarre guesses such as 'meat', 'mist' etc. It became clear that they were basing their guess on only the two end letters: m____t. There are over 40 words that share that pattern.

Other children were even worse readers because they were obviously basing their guess on just the first letter. They misread 'magnet' as 'mother', 'measles' or any of 400 possible words beginning with m-----.

We therefore developed a method of measuring how many of these high visibility letters each indivual child was holding in memory. We called this the VAS (Visual Attention Span) level and the Harrison test is today the only means of measuring a child's capacity to word-guess. If you encourage word-guessing without first understanding the VAS level you may unwittingly CAUSE bad reading habits.

To gain further understanding of VAS Theory click on the link the right hand side bar on this page.