Elderly text-entry performance on touchscreens

ABSTRACT

Touchscreen devices have become increasingly popular. Yet they lack of tactile feedback and motor stability, making it difficult effectively typing on virtual keyboards. This is even worse for elderly users and their declining motor abilities, particularly hand tremor. In this paper we examine text-entry performance and typing patterns of elderly users on touch-based devices. Moreover, we analyze users' hand tremor profile and its relationship to typing behavior. Our main goal is to inform future designs of touchscreen keyboards for elderly people. To this end, we asked 15 users to enter text under two device conditions (mobile and tablet) and measured their performance, both speed- and accuracy-wise. Additionally, we thoroughly analyze different types of errors (insertions, substitutions, and omissions) looking at touch input features and their main causes. Results show that omissions are the most common error type, mainly due to cognitive errors, followed by substitutions and insertions. While tablet devices can compensate for about 9% of typing errors, omissions are similar across conditions. Measured hand tremor largely correlates with text-entry errors, suggesting that it should be approached to improve input accuracy. Finally, we assess the effect of simple touch models and provide implications to design.

References

1. Bain et al. Assessing the impact of essential tremor on upper limb function. Journal of neurology, 241(1):54--61, 1993.
2. Bergstrom-Lehtovirta et al. The effects of walking speed on target acquisition on a touchscreen interface. In Proc. of MHCI'11, 143--146, 2011.
3. Chung et al. Usability evaluation of numeric entry tasks on keypad type and age. International Journal of Industrial Ergonomics, 40(1):97--105, 2010.
4. Elble and Koller. Tremor. Johns Hopkins University Press Baltimore, 1990.
5. Findlater and Wobbrock. Personalized input: Improving ten-finger touchscreen typing through automatic adaptation. In Proc. of CHI'12, 815--824, 2012.
6. Froehlich et al. Barrier pointing: using physical edges to assist target acquisition on mobile device touch screens. In Proc. of ASSETS'07, 19--26, 2007.
7. Goetz et al. Movement disorder society-sponsored revision of the unified parkinson's disease rating scale (mds-updrs): Scale presentation and clinimetric testing results. Movement disorders, 23(15):2129--2170, 2008.
8. Gunawardana et al. Usability guided key-target resizing for soft keyboards. In Proc. of IUI'10, 111--118, 2010.
9. Jin et al. Touch screen user interfaces for older adults: button size and spacing. Universal Acess in Human Computer Interaction. Coping with Diversity, 933--941, 2007.
10. Kristensson. Five challenges for intelligent text entry methods. AI Magazine, 30(4):85, 2009.
11. Kurniawan. Older people and mobile phones: A multi-method investigation. International Journal of Human-Computer Studies, 66(12):889--901, 2008.
12. MacKenzie and Soukoreff. Text entry for mobile computing: Models and methods, theory and practice. Human-Computer Interaction, 17(2):147--198, 2002.
13. Nicolau and Jorge. Touch typing using thumbs: understanding the effect of mobility and hand posture. In Proc. of CHI '12, 2683--2686, 2012.
14. Salarian et al. Quantification of tremor and bradykinesia in parkinson's disease using a novel ambulatory monitoring system. Biomedical Engineering, IEEE Transactions on, 54(2):313--322, 2007.
15. Selker et al. Psychosocial indicators via hand tremor. In Proc. of INTERACT'11, 596--599, 2011.
16. Strickland and Bertoni. Parkinson's prevalence estimated by a state registry. Movement disorders, 19(3):318--323, 2004.
17. Wacharamanotham et al. Evaluating swabbing: a touchscreen input method for elderly users with tremor. In Proc. of CHI'11, 623--626, 2011.
18. Wobbrock et al. EdgeWrite: a stylus-based text entry method designed for high accuracy and stability of motion. In Proc. of UIST'03, 70, 2003.

Index Terms

• Human-centered computing

  • Human computer interaction (HCI)

    • Interaction devices

      • Touch screens