Proficient blind users and mobile text-entry

ABSTRACT

Motivation -- Understand how NavTap, an assistive text-entry method, stands in relation to traditional approaches.

Research approach -- We performed a between-subjects text-entry study with 12 blind users proficient with MultiTap and five blind users proficient with NavTap. Participants were asked to input ten sentences with different length and complexity.

Findings/Design -- MultiTap significantly outperformed NavTap when considering text entry speed, confirming its theoretical advantage. However, when considering method effectiveness, NavTap's less experienced participants committed significantly fewer errors, indicating that it is both easier to learn and use, reaffirming it is an alternative for those unable to adjust to demanding adaptations.

Research limitations/Implications -- Before NavTap appeared its users were unable to input text in a mobile device. Indeed, existing data make it difficult to assess differences between the users of either method. Further, NavTap users had less experience using the method (four months) than MultiTap (years).

Originality/Value -- We contribute to understanding the limitations and merits of different text-entry approaches for blind people, after extensive usage.

Take away message -- Different methods have different limitations and values. Selecting a match for a particular user may depend on his individual differences.

References

1. Guerreiro, T., Lagoá, P., Santana, P., Nicolau, H., and Jorge, J. (2008). Mobile Text-Entry Models for People with Disabilities. European Conference on Cognitive Ergonomics 2008, Madeira, Portugal.
2. Guerreiro, T., Nicolau, H., Jorge, J. and Gonçalves, D. (2009). NavTap: a Long Term Study with Excluded Blind Users. In Proc. of SIG ASSETS, AMC Press.
3. MacKenzie, I. S., and Tanaka-Ishii, K. (2007). Text Entry Systems: Mobility, Accessibility, Universality. Morgan Kaufmann Publishers Inc.
4. Silfverberg, M., MacKenzie, I.S, and Korhonen, P. (2000). Predicting text entry speed on mobile phones. In Proc. SIG CHI, ACM Press.
5. World Health Organization (2008). Magnitude and causes of visual impairment. http://www.who.int/mediacentre/factsheets/fs282/(Last Visited on 29/03/2010)

Index Terms

• Applied computing

  • Computers in other domains

    • Personal computers and PC applications

• Human-centered computing

  • Accessibility

  • Human computer interaction (HCI)

    • Empirical studies in HCI

    • Interaction devices

      • Touch screens