Text prediction is one of the most widely used technique to enhance the text entry rate in message composition system with virtual keyboard. Several text prediction techniques have been reported in recent literature. Most of them concentrate on prediction method and keystroke savings. It is observed that other than these issues, many factors influence the performance of text prediction. This paper discusses these different parameters. In addition to prediction method, we also examine organizational structure and fast retrieval of suggestion, factor such as User Interface and Human factors, such as orientation of prediction list, number of suggestions to be displayed, proper placing of prediction window, training and testing etc. Issues such as keyboard-adjacency and motor-coordination slip are also illustrated. In this paper we elaborate the proper placing of displaying prediction list for maximum benefit and its effect on searching the word in the predictive text entry system.