Shinji Moriya

Efficient Strategies for Selecting Small Targets on Pen-based Systems: An Evaluation Experiment for Selection Strategies and Strategy Classifications

This paper describes six strategies for selecting small targets on pen-based systems. We have classified the strategies into strategy groups according to their characteristics. An experiment was conducted comparing selection time, error rate and user preference ratings for the six selection strategies. We focused our attention on the three variables associated with pen-based selection: size, direction and distance to target. Three target sizes, eight pen-movement-directions and three pen-movement-distances were applied to all six strategies. Experimental results show that the best strategy was the “Landon2” strategy when the strategies were evaluated individually, and the best strategy group was the “In-Out” strategy group when evaluated in groups. Analyses also showed that differences between strategies were influenced by variations in target size, however, they were not influenced by pen-movement-distance and pen-movement-direction. Analyses of grouped strategies produced the same results. Ideas for future research are also presented.

The Best among six Strategies for Selecting a Minute Target and the Determination of the Minute Maximum Size of the Targets on a Pen-Based Computer

This study concentrates on finding the relationship between target-pointing strategies and target sizes. Concretely, an evaluation experiment was performed in which the experimental system used five kinds of targets (1, 3, 5, 7 and 9 dot diameter circles in respectively, 0.36 mm per dot), eight pen-movement-directions and six strategies of systematic election on a pen-based computer. The results showed that the “Land-on2” strategy was the best strategy for selecting a minute target, in terms of error rates, selection time and subjective preferences. “The minute maximum size” of 5 dots was also determined to be the largest size among the targets which had a significant main effect on the six strategies in terms of error rates.

The Influence of Target Size, Distance and Direction on the Design of Selection Strategies

The influence of various parameters on the design of selection strategies was investigated. Our question is, do changes in the size, distance or direction to a target affect the differences in performance between selection strategies? We performed an experiment on a pen-based system to evaluate the effect of size, distance and direction on six strategies for selecting a target. Three target sizes, three pen-movement-distances, and eight pen-movementdirections were applied to all six strategies. The results show that the differences between selection strategies are affected by target size (when target size decreases below a certain size, differences between selection strategies appear; conversely, differences between selection strategies disappear when target sizes are increased beyond a certain size). The results also show that the differences between selection strategies are not affected by pen-movement-distance and pen-movement-direction. Issues relating to the merits of individual strategies will be the focus of planned future investigations.

A telewriting system on a LAN using a pen-based computer as the terminal

The system we developed is software for implementing a “telewriting” terminal. Here, we propose a method for implementing this telewriting terminal as an application program running on pen-based computers. “Telewriting” is a technology in which the ink data (written with a pen on one terminal) is transmitted in real time to other terminals and displayed on their monitors. When this process is carried out between two terminals in both directions, two usem using telewnting terminals can mutually and simultaneously transmit and view visual information. If two usem can use a combination of this telewriting and telephone, they can send to and receive fl-om each other audio-visual information in real time. Consequently, two users can communicate smoothly without having to interrupt their flow of conversation. Already, there are some systems which can be used to conduct telewriting and othem called shared drawing tools. Examples are Displayphone (Bell Telephone Laboratory, U.S.A.), Scribophone (Philip& Holland), Sketchphone (NIT, Japan), MERMAID (NEC, Japan), Commune station (Xerox Palo Alto Research Center, U.S.A.), etc. These systems are only used for conducting telewnting, or as multi-media communication systems in which telewriting is just a minor function, or as systems for studying cooperative work in distributed environment. At present, none of these systems is being widely used. We presume that the two reasons why these systems have not enjoyed widespread are, these terminals are expensive and also because of the minimal opportunities for using them. We think that, in order to make telewnting more widespread, it (i.e. telewriting) should be developed and implemented as one of the application programs for pen-based computers. We believe that our research is significant because it proposes a method for implementing a telewriting system and also shows how a pm-based computer can be used as a tool towards the realization of such a system. The telewriting system we developed can be used by connecting the terminal (pen-based computer) to LAN (Ethernet). At present, we are testing our system on the LAN in Tokyo Denki University. Also, we are using the telephone (within our university) in combination with