SUS: A System Unusable for Twenty Percent of the Population

Key Insights

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  Assistive technologies mainly split into screen readers, screen magnifiers, and alternative navigation devices, each with distinct user needs.

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  Screen reader users heavily rely on semantic web structure and proper labeling for efficient navigation.

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  Magnification users often supplement their experience with screen reader features to reduce eye strain.

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  Alternative navigation users use multiple input methods like voice commands and head mice, providing fallback options.

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  Traditional usability labs and standard SUS questionnaires fail to consider unique accessibility challenges and setup of assistive tech users.

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  SUS questions like needing technical support or learning speed are confusing or irrelevant to assistive tech users without adaptation.

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  Fable created the Accessible Usability Scale to better evaluate assistive tech user experience by adapting question language and scope.

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  Preliminary AUS data indicates screen reader users experience the lowest usability scores due to lack of backup input methods.

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  Remote usability testing greatly increases participation and authentic results by allowing users to test in familiar, customized environments.

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  User skill with assistive tech, experience level, and mental models vary significantly and must be considered beyond linear novice-expert scales.

Notable Quotes