Pen Input Based Measures

Abstract

Writing, as a complex form of interaction, often entails intensive user attention and cognitive load. This chapter discusses cognitive load examinations involving handwriting, with a focus on the behavioral features which involve writing velocity, pressure, pen gesture and some features derived from them. Based on the cognitive load examination of different scripts including text, digits and sketches, it is suggested that the behavioral features for cognitive load examination is content dependent and sometimes writing direction dependent. Specifically, this chapter discusses the following issues:• Handwriting datasets for cognitive load examination, each focused on text writing, digit writing and sketching respectively; • Writing features to examine cognitive load at stroke, sub-stroke or point levels;• Implications of cognitive load on writing shape.The discussed investigation methods to classify cognitive load levels are a first step towards a practical cognitive load aware writing system, and the preliminary results are likely to be further improved with more complex and refined methods. Writing Based MeasuresWriting behaviors involve the movement of the fingers and arm, the way strokes are generated and the pressure exerted on the pen. The first question posed is what the roles of the fingers and wrist play during writing. The biomechanical explanation for finger and arm movements is that each joint functions like a hinge or a universal joint. The hinge allows for movement control in one single direction, while the universal joint supports the movements of multiple directions. The wrist is a typical hinge and can only rotate a limited angle during writing. The fingers, however, are much more versatile as a combination of hinges and universal joints, with two or more degrees of freedom [1]. The difference in biomechanical properties between