Input Behavior When Using Two Fingers on a Multi-Touch Device

ABSTRACT

The purpose of this study is to analyze device input patterns using fingers in multi-touch mode and to derive Fitts’ law for multi-touch methods. Three specific input behaviors—dragging, rotating, and pinching—are investigated. Test participants performed two Fitts’ law experiments, a single-touch experiment using the thumb only and a multi-touch experiment using both the thumb and index finger. Within-subject factorial design was implemented with two levels of touch behavior (single-touch) and three levels of touch behavior (multi-touch), six levels of the index of difficulty (ID), four levels of direction, and two levels of repetition. The results indicate that a revised model of Fitts’ law is more appropriate for the multi-touch mode, achieving R² values above 0.895, and identifying the best nonlinear model among several regression models. The results of this study are used to determine the relationship between ID and movement time in terms of Fitts’ law and to investigate whether this relationship is sufficient to serve as a model to predict movement times. This study contributes to the prediction of movement times for products with multi-touch interfaces.

Additional information

Notes on contributors

Jaekyu Park

Jaekyu Park is a Ph.D. candidate at the Department of Industrial Management Engineering, Korea University, Seoul, South Korea. He received an MS in Industrial System and Information Engineering from Korea University. His current research interests mainly focus on human–computer interaction.

Sungjoon Park is a professor at the Department of Industrial Management Engineering, Namseoul University, Cheonan, Chungcheongnam-do, South Korea. He received a PhD in Industrial Engineering from POSTECH and was in charge of package design at Samsung Motors. His research interests include product development, automotive ergonomics, affection design, and human–computer interaction.

Eui S. Jung

Eui S. Jung is a professor at the Department of Industrial Management Engineering, Korea University, Seoul, South Korea. He received a PhD in Industrial and Manufacturing Engineering from Penn State University. His research interests include product development, ergonomic design, and human–machine interaction.

Sungjoon Park

Jaekyu Park is a Ph.D. candidate at the Department of Industrial Management Engineering, Korea University, Seoul, South Korea. He received an MS in Industrial System and Information Engineering from Korea University. His current research interests mainly focus on human–computer interaction.

Sungjoon Park is a professor at the Department of Industrial Management Engineering, Namseoul University, Cheonan, Chungcheongnam-do, South Korea. He received a PhD in Industrial Engineering from POSTECH and was in charge of package design at Samsung Motors. His research interests include product development, automotive ergonomics, affection design, and human–computer interaction.