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Now you see it, now you don’t

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conference contribution
posted on 12.05.2009, 13:19 by Edward Elton, Colette Nicolle
This paper details a study that was conducted to determine the effect physical context of use, e.g. daily lighting levels and contrast, has on perception. The study was undertaken to further develop inclusive design analytical tools that assess the characteristics of a product against the capabilities of users. A total of four lighting levels were tested (equivalent to street lighting, in-house lighting, optimum and daylight), and four contrast levels (90%, 50%, 25% and 10% contrast). A random proportionate sample of adults aged 65 years and older was drawn from the population (N = 38, age range 65-87 years, mean age 74). The experiment revealed daily lighting levels to have a noticeable affect on visual acuity. Results showed that by increasing the lighting level from street lighting to optimum, there was an increase of up to 44% in the number of participants able to correctly read particular rows of letters. In 73% of cases the number of people able to correctly read each letter size decreased when its contrast was reduced. With certain letter sizes up to 50% more people were able to read letters at 90% compared to 10% contrast. Future work is being planned to see how these results relate to the general population and everyday products.



  • Design


ELTON, E. and NICOLLE, C.A., 2009. Now you see it, now you don't. INCLUDE 2009, International Conference on Inclusive Design, Royal College of Art, London, UK, 5-8 April


The Helen Hamlyn Research Centre / Include

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This conference paper was presented at Include 2009, please visit for more details.



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