Children's interaction with touchscreen devices: Performance and validity of Fitts' law

Abstract

Interaction of human beings with various types of apparatus, including many digital gadgets, follows Fitts' law. The objectives of this study were to assess the ability of children to acquire onscreen targets while using smartphones and determine if their interaction with smartphones follows Fitts' law. We developed an app implementing the standard two-dimensional target selection task and provided it to 30 children aged between 4 and 10 years. We observed them to use the app and acquire onscreen targets using the tap gesture and the drag and drop gesture. We noted the index of difficulty (ID), movement time (MT), and throughput (TP) for the movement tasks. MT decreased and TP increased with the age of the children (p