Design and Evaluation of User-friendly yet Efficient Sinhala Input Methods
Sandeva Goonetilleke · OUKA (Osaka University Knowledge Archive) (Osaka University) · 2009
This thesis is a compilation of research results of the author, regarding Sinhala input systems, during his doctoral program in the Graduate School of Information Science and Technology of Osaka University, from 2006.Sinhala, spoken in Sri Lanka as an official language, is one of the less privileged languages; still there are no established text input systems.Equipped with an adequate input system is crucially important in computing in Sinhala; here computing in Sinhala simply means to utilize computers with Sinhala language.Without such a device, ideas originated from Sinhala people cannot be fully verbalized, and hence will not be disseminated to the world.As with many of the Asian languages, Sinhala also has a large set of characters, forcing us to develop an input system that can properly address the issue.The main objective of this research is to propose a highly user-friendly yet efficient Sinhala text input system.The targeted users of the system are the general Sinhala computer users, who have an average-level of knowledge about computers, and are familiar with Roman character keyboards.We have approached to this goal by implementing two systems: Sri Shell, a phonetically-principled system, and SriShell Primo, a word-based predictive system.To be user-friendly, Sri Shell is based on a phonetically-principled key assignments, while SriShell Primo is equipped with a mechanism that accepts userintuitive key sequences.Another objective of this research is to establish adequate measures for evaluating the user-friendliness and efficiency of Sinhala input systems, because we think the userfriendliness is quite important, given the targeted users.To this end, we propose an efficiency measure that quantifies the average typing cost per Sinhala character.We also propose a user-friendliness measure that evaluates the intuitiveness of required/acceptable key sequences.These measures are proven useful in evaluating existing Sinhala input systems as well as the proposed two systems.This thesis consists of six chapters, and is organized as follows.Chapter 1 gives a brief introduction on Sinhala language and summarizes the use of computers in Sinhala.Based on the argument, our research motivation is stated.Also the organization of this thesis is given.Chapter 2 provides necessary background information to understand the presented research: linguistic nature of Sinhala language and classification of text input systems.This •Efficiency •User-friendliness Evaluation Methodology (Chapter 3)