Mobile Text Entry Methods Research Articles

Using analytic network process for evaluating mobile text entry methods

This paper highlights a preference evaluation methodology for text entry methods in a touch keyboard smartphone using analytic network process (ANP). Evaluation of text entry methods in literature mainly considers speed and accuracy. This study presents an alternative means for selecting text entry method that considers user preference. A case study was carried out with a group of experts who were asked to develop a selection decision model of five text entry methods. The decision problem is flexible enough to reflect interdependencies of decision elements that are necessary in describing real-life conditions. Results showed that QWERTY method is more preferred than other text entry methods while arrangement of keys is the most preferred criterion in characterizing a sound method. Sensitivity analysis using simulation of normally distributed random numbers under fairly large perturbation reported the foregoing results reliable enough to reflect robust judgment. The main contribution of this paper is the introduction of a multi-criteria decision approach in the preference evaluation of text entry methods.

Multi-Criteria Evaluation Approach of Mobile Text Entry Methods

Current evaluations on mobile text entry methods focus only on speed and accuracy performance but fail to consider subjective preferences of users. Such evaluation is ill-defined and does not constitute a systems approach since it requires a complex multi-criteria decision process that must encompass both objective and subjective criteria. Thus, this paper proposes the use of Analytic Network Process (ANP) in the evaluation of five mobile text entry methods in Android smartphones. A hierarchical network decision problem is developed from a focus group discussion of keen smartphone users. Using ANP, new insights in research and design of text entry methods are proposed. Results show that QWERTY method is the most preferred text entry method and is influenced by criteria on perceived text entry speed and number of keys. A survey is conducted to validate the results of the evaluation process using ANP. The main contribution of this work is in introducing a multi-criteria evaluation approach for mobile text entry research that holistically addresses speed-accuracy performance along with relevant subjective criteria that may potentially influence decision-making.

Escape-Keyboard

Mobile text entry methods traditionally have been designed with the assumption that users can devote full visual and mental attention on the device, though this is not always possible. The authors present their iterative design and evaluation of Escape-Keyboard, a sight-free text entry method for mobile touch-screen devices. Escape-Keyboard allows the user to type letters with one hand by pressing the thumb on different areas of the screen and performing a flick gesture. The authors then examine the performance of Escape-Keyboard in a study that included 16 sessions in which participants typed in sighted and sight-free conditions. Qualitative results from this study highlight the importance of reducing the mental load with using Escape-Keyboard to improve user performance over time. The authors thus also explore features to mitigate this learnability issue. Finally, the authors investigate the upper bound on the sight-free performance with Escape-Keyboard by performing theoretical analysis of the expert peak performance.