Essay --

NAME: SHASHEEN POTHULA UMID: 17726116 1.) Zhai and Kristensson identify five motivating principles for their design. Consider T-9 input for entering text on a cell phone keypad, in predictive text mode. How would a proponent of T-9 address these principles? Do all apply? Text input constitutes one of the most frequent computer user tasks. Several input techniques were developed from QWERTY keyboard to the hand writing recognition systems and the virtual keyboards, but all of them have limitations. Shumin Zhai and Per-Ola Kristensson have proposed in their paper a new method that can help in fast typing for large vocabulary. They named their method SHARK which is stand for shorthand aided rapid keyboarding. This method basically offered writing on keyboard by identifying the typing gestures. It also defines and recognizes a symbol for each word by the way of movement pattern that it has been typed without taping on letters. The key five motivating principles involved in SHARK design are: ïÆ'Ëœ Scale and location independency ïÆ'Ëœ Efficiency ïÆ'Ëœ Durability ïÆ'Ëœ Zipf’s law effect ïÆ'Ëœ Transition from tapping to gesturing Predictive text entry is used to try to predict the word a user is typing before they ï ¬ nish entering all its characters. One or more predictions are normally presented to the user as they type, allowing them to select a correct choice before they ï ¬ nish entering their word. When successful, predictive text entry can improve both speed and accuracy. T9 short for Text on 9 keys—was one of the ï ¬ rst predictive text methods, used on feature phones with a number pad, where each number corresponds to multiple letters, identical to the number-to-letter mapping used on traditional landline phones. Prior to T9, users would e... ...ctive to learning stylus keyboarding although the rate of expansion and the unit of training in stylus keyboarding needed further investigation. Speed writing is an old research topic with renewed interest due to the need of using mobile computing devices. To write a significant amount of text, natural writing is too slow and stylus keyboarding is tedious and visually demanding. Usually there are two types of classes namely novice and experts. The novice users may find a little difficult to memorize the gestures but the experts does not feel so. But in the case of SHARK, even the novice users were able to memorize and started using the gestures with in less time and the number of words typed per minute increased drastically. By this we can say that SHARK can be used by every user with less hard work and it is one of the best human interfaces used for words typing.