Rather, Jeanes et al. (1997) suggested that an increase of >8% in reading rate with an overlay may provide a better indication of a benefit of the use of overlays. It is reasonable to assume that the experience of visual discomfort and perceptual distortions would interfere not only with reading accuracy and fluency but also with comprehension. In a preliminary test of this hypothesis, Lewis and Wilkins (unpublished data, cited in Wilkins, 2002) found that reading speed and speed of comprehension of connected text were improved by overlays. However, while it is acknowledged that improving reading rate per se could be helpful, it remains unclear whether this improvement extends to measures of reading and accuracy comprehension, both skills are critical for students at university who are often recommended overlays. Given that an improvement in reading rate with an overlay is frequently used as a means of identifying visual stress, it is important to demonstrate that the reliability of overlay testing with WRRT is high. Wilkins et al. (1996) tested children on the WRRT, using the Intuitive Overlays, at the beginning and at the end of the summer term (after 8 weeks). Approximately 40% of the children who chose an overlay at the beginning of the summer term were still using it at the end of the term. The correlation between reading rate without a coloured overlay at each testing point was high (r = .83), but the correlation between the improvement obtained at each testing point was not reported. According to Wilkins et (1996) the overlay benefit increased according to al. the frequency with which the children used it. Wilkins et al. (2001) reported that 87% of children chose a coloured overlay on two different sessions but only 47% of these children chose the same colour. Nevertheless, the improvement in reading with an overlay was strongly correlated between the two sessions (r=.72), implying good reliability in children.
Rather, Jeanes et al. (1997) suggested that an increase of >8% in reading rate with an overlay may provide a better indication of a benefit of the use of overlays. It is reasonable to assume that the experience of visual discomfort and perceptual distortions would interfere not only with reading accuracy and fluency but also with comprehension. In a preliminary test of this hypothesis, Lewis and Wilkins (unpublished data, cited in Wilkins, 2002) found that reading speed and speed of comprehension of connected text were improved by overlays. However, while it is acknowledged that improving reading rate per se could be helpful, it remains unclear whether this improvement extends to measures of reading accuracy and comprehension, both skills are critical for students at university who are often recommended overlays. Given that an improvement in reading rate with an overlay is frequently used as a means of identifying visual stress, it is important to demonstrate that the reliability of overlay testing with WRRT is high. Wilkins et al. (1996) tested children on the WRRT, using the Intuitive Overlays, at the beginning and at the end of the summer term (after 8 weeks). Approximately 40% of the children who chose an overlay at the beginning of the summer term were still using it at the end of the term. The correlation between reading rate without a coloured overlay at each testing point was high (r = .83), but the correlation between the improvement obtained at each testing point was not reported. According to Wilkins et al. (1996) the overlay benefit increased according to the frequency with which the children used it. Wilkins et al. (2001) reported that 87% of children chose a coloured overlay on two different sessions but only 47% of these children chose the same colour. Nevertheless, the improvement in reading with an overlay was strongly correlated between the two sessions (r=.72), implying good reliability in children.