With the rapid spread of Indian language content on the web, user input oriented applications in Indian languages are also becoming popular. There is an increasing need for efficient and user friendly input interfaces to type in Indian languages. However, despite the obvious need and significance, text input has not been studied and researched so far, in the context of Indian languages. In this thesis, we study the problem of text input for Indian languages, by taking Telugu as the test case. Owing to the similarity among Indian languages, the results of this work can be applied with necessary changes, to other Indian languages as well. We have first classified data input systems in to four categories - keyboard layouts, input method editors, prediction systems and soft keyboards.

In the first category, we have designed some keyboard layouts for Telugu, based on a set of design principles formed after a study of the relevant literature. We have then evaluated them based on the set of evaluation measures and concluded that our designs work better than the existing solutions, thereby providing efficient alternatives to the present day Telugu keyboard. In the context of input method editors, we have studied the different mappings available to convert between Indian languages and Roman script, and compared them with our new mapping, in an attempt to find out a mapping closest to human intuition. We have concluded that though there is no significant difference in performance with different mappings, Rice Transliteration Scheme has a better ease of remembrance compared to other mappings. We have studied the problem of text prediction for Indian language input and proceeded towards developing transliteration based prediction approach to text input in Telugu. We have proved that a simple approach like edit-distance based text prediction works very well as a text input method and offers a light weight and efficient system. Finally, we have worked on the design and evaluation of soft keyboards for Telugu. Our designs worked better than the existing soft keyboards for Telugu. Thus, we have successfully proposed efficient text input methods for Telugu which can be good alternatives to existing input methods.