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According to Fitts' law, human movement can be modeled by analogy to the transmission of information. Fitts' popular model has been widely adopted in numerous research areas, including kinematics, human factors, and (recently) human-computer interaction (HCI). The present study provides a historical and theoretical context for the model, including an(More)
This paper makes seven recommendations to HCI researchers wishing to construct Fitts' law models for either movement time prediction, or for the comparison of conditions in an experiment. These seven recommendations support (and in some cases supplement) the methods described in the recent ISO 9241-9 standard on the evaluation of pointing devices. In(More)
Text input for mobile or handheld devices is a flourishing research area. This article begins with a brief history of the emergence and impact of mobile computers and mobile communications devices. Key factors in conducting sound evaluations of new technologies for mobile text entry are presented, including methodology and experiment design. Important(More)
The design and evaluation of a high performance soft keyboardfor mobile systems are described. Using a model to predict theupper-bound text entry rate for soft keyboards, we designed akeyboard layout with a predicted upper-bound entry rate of 58.2wpm. This is about 35% faster than the predicted rate for a QWERTYlayout. We compared our design (OPTI) with a(More)
KSPC is the number of keystrokes, on average, to generate each character of text in a given language using a given text entry technique. We systematically describe the calculation of KSPC and provide examples across a variety of text entry techniques. Values for English range from about 10 for methods using only cursor keys and a SELECT key to about 0.5 for(More)
In evaluations of text entry methods, participants enter phrases of text using a technique of interest while performance data are collected. This paper describes and publishes (via the internet) a collection of 500 phrases for such evaluations. Utility programs are also provided to compute statistical properties of the phrase set, or any other phrase set.(More)
An experiment is described comparing three devices (a mouse, a trackball, and a stylus with tablet) in the performance of pointing and dragging tasks. During pointing, movement times were shorter and error rates were lower than during dragging. It is shown that Fitts' law can model both tasks, and that within devices the index of performance is higher when(More)
In view of the difficulties in evaluating computer pointing devices across different tasks within dynamic and complex systems, new performance measures are needed. This paper proposes seven new accuracy measures to elicit (sometimes subtle) differences among devices in precision pointing tasks. The measures are target re-entry, task axis crossing, movement(More)
The IS0 9241, Part 9 Draft International Standard for testingcomputer pointing devices proposes an evaluation of performance andcomfort. In this paper we evaluate the scientific validity andpracticality of these dimensions for two pointing devices forlaptop computers, a finger-controlled isometric joystick and atouchpad. Using a between-subjects design,(More)