Framework

next page

Overview | Model | Assessing | Disability survey (5) | Demand (2) | Using guidance | Example

Demand & exclusion

The basics | Further details

The data from the Disability Follow-Up Survey can also be presented in a format suitable for assessing design exclusion directly, where the ability level that a product demands in order to use it is directly plotted against the number of people who will be excluded.

For example, with regard to vision demand, approximately 1% of the GB adult population would be excluded from a product that requires the user to see well enough to read a newspaper headline.

The Disability Follow-Up Survey does not make any reference to the environment, or to fatigue caused by repeated actions. Until better data is obtained, these factors can only be accounted for by using judgement to modify the demand level appropriately

Estimating the number of people who would be unable to use a product based on multiple different capability demands requires an exclusion calculator, such as the one on this website.

No demand

  • The user is not required to perceive anything by sight

Low demand

The user is required to have sufficient ability to do things like

  • Read a newspaper headline (≈ 72 pt text)
  • Recognise a friend at arm's length away
Example graph showing percentages of GB adult population versus Vision demand levels

Vision demand levels, and the corresponding number of people who would be excluded due to these demands