One-handed thumb use on smart phones by semi-literate and illiterate users in India: A usability report with design improvements for precision and ease

ABSTRACT There is tremendous potential for developing mobile-based occupational productivity tools for semi-literate and illiterate users in India. One-handed thumb use on the touchscreen of smart phone or touch phone is considered as an effective alternative than the use of stylus or index finger, to free the other hand for supporting occupational activity. In this context, usability research and experimental tests are conducted to understand the role of fine motor control, usability of thumb as the tool for interaction and the ergonomic needs of users. The paper touches upon cultural, racial and anthropometric needs related with the topic, which also need due consideration while designing the mobile interface. Design recommendations are evolved to improve overall effectiveness of one-handed thumb use on smart phone, especially for the benefit of semi-literate and illiterate users.