Touchable area: An empirical study on design approach considering perception size and touch input behavior

• Design approach was examined for increasing interaction with touch user interface.
• We investigate the characteristics of touch input behavior.
• Touchable area with a desirable hit rate of 90% was empirically derived.
• Flexibility of a touchable area was verified based on analysis of user errors.

As the use of mobile touch devices continues to increase, distinctive user experiences can be provided through a direct manipulation. Therefore, the characteristics of touch interfaces should be considered regarding their controllability. This study aims to provide a design approach for touch-based user interfaces. A derivation procedure for the touchable area is proposed as a design guideline based on input behavior. To these ends, two empirical tests were conducted through a smart phone interface. Fifty-five participants were asked to perform a series of input tasks on a screen. As results, touchable area with a desirable hit rate of 90% could be yielded depending on the icon design. To improve the applicability of the touchable area, user error was analyzed based on omission-commission classification. The most suitable design had a hit rate of 95% compared to 90 and 99%. This study contributes practical implications for user interaction design with finger-based controls.Relevance to industryThis research describes a distinctive design approach that guarantees the desired touch accuracy for effective use of mobile touch devices. Therefore, the results will encourage interface designers to take into account the input behavior of fingers from a user-centered perspective.