Design and evaluation of handwriting input interfaces for small-size mobile devices

This paper deals with the design of handwriting input methods for small-size mobile devices. A first input method using the isolated cursive handwritten character recognizer RESIFCar has been embedded into smartphones sold in Europe. This industrial feedback has shown the importance of the interface quality even if the associated recognizer reaches good recognition rates. Consequently, we focus our researches on the design of handwriting input interfaces for small-size devices. The originality of our works comes from the integration of the user in the interface design process with an iterative implementation-evaluation cycle. The interface quality is evaluated thanks to experiments base on the cognitive psychology framework. We present here the first iteration of the design cycle of DIGIME, the DIGital Ink Micro Editor associated to RESIFCar. We start with a quick overview of the existing handwriting input methods. Then we present our handwritten character recognizer RESIFCar and establish a set of design principles for handwriting input interfaces. After detailing the main features of the first DIGIME prototype based on these principles, we describe its evaluation. This study examines the effect of ink writer’s persistence on the screen and the effect of visual feedback contiguity. The results of this study have emphasized some problems in the implementation choices. So, we proposed a second version of DIGIME in order to improve the quality of the interface and give some hints for the future evaluation of this new prototype.