Touch-sensitive displays have become very popular with the advent of smartphones and tablets. Most smartphones and tablets are designed for multi-touch finger control. Displays with stylus or light pen input predate the modern multi-touch displays but became less popular for a variety of reasons, one of which is that their usability and user experience was not good. Stylus usability was limited by the available technology. In recent years stylus input devices have become more capable and popular. In particular, they are not only used for navigation and minor input, they are becoming popular for content creation in the form of sketching and handwriting. Recent stylus-tablet combinations from Microsoft and Apple, among others, specifically target content creation. However, the technical performance of the latest devices is still less than completely desirable, particularly in the areas of latency, accuracy and precision. As stylus input devices grow in popularity and become a growing part of Information Technology these aspects need more understanding. This study investigates the quantitatively measurable usability characteristics of stylus performance with particular emphasis on latency and accuracy. Latency and positioning accuracy are measured for a few current technology stylus/tablet combinations with different operating systems and application software packages. We find that the line-drawing mechanism exhibits an unexpected step-wise behavior and that there are still significant latency and accuracy delays and other anomalies, as well as other concerns. While modern stylus/tablet systems give generally satisfactory performance there is room for improvement.
['Richard G. Helps', 'Clarissa Helps']
Measuring Stylus and Tablet Performance for Usability in Sketching