Toshiyuki Asahi

Camera-typing interface for ubiquitous information services

We propose a new technology called the camera-typing interface, which can read printed characters such as URLs with a low-resolution camera. It realizes a type of ubiquitous information service using smart phones with cameras. This method includes two main advantages: automatic concatenation of sequential shots and automatic error correction by re-shooting. The automatic concatenation enables a user to take segmented images of a character string, thus a low-resolution camera can be used as the interface device. The automatic error correction enables the user to correct misrecognized characters just by retaking images around them, providing an easy and natural way of error correction. We present two experimental results to prove effectiveness of our method. Both results indicate that our proposed method is helpful.

Variation in importance of time-on-task with familiarity with mobile phone models

We studied the extent to which time-on-task is correlated with perception of usability for people who are familiar with a phone model and for those who are not. Our controlled experiment, conducted in Japan, correlated subjective usability assessments with time-on-task for expert and novice users on three different mobile phone models. We found that the correlation between perceived usability and time-on-task is stronger when participants are more familiar with the phone model. While not significant when initially inspecting a new phone model, a negative correlation between time-on-task and perceived usability becomes significant with as little as an hours time doing tasks on the unfamiliar phone. This suggests that designing the UI to make time-on-task as short as possible may not have much effect on the purchase decision, but as experience increases, it may increase the loyalty of existing users.

A Usability Evaluation Method Applying AHP and Treemap Techniques

This report proposes a visualization technique for checklist-based usability quantification methods. By applying the Treemap method, the hierarchical structure of checklists, weights of check items and evaluation results for target systems can be viewed at a glance. Effective support for usability analysis and its presentation tasks of usability evaluation results are expected. A prototype tool was implemented on a PC and experimental studies assuming actual usability evaluation tasks were conducted. The results indicate that the proposed method improves performance time of some typical tasks. Usability engineers gave higher subjective scores on the usefulness of the proposed method than that of printed table presentation.

Tools for Iterative User Interface Design: UI-tester and OST

Abstract A computer-aided iterative design environment is proposed. A usability testing tool “UI-tester” and a user interface design tool “OST” are integrated so that iterative design programs can be effectively implemented in the early stage of product development without usability expertise. A feasibility study being conducted on an ongoing facsimile product development project in this environment gives data showing that common erroneous pattern extraction functions of UI-tester are applicable for identifying user interface problems, and that user interface redesigns are completed without additional delays in the product development cycle.

A Usability Testing Method Employing the “Trouble Model”:

This paper proposes a technique to apply the protocol analysis method to usability testing. The “trouble analysis” method is offered for data analysis tasks. These techniques involve a procedure to improve time efficiency and convenience. As a criterion for data analysis, a “trouble model”, which consists of 22 trouble categories, is also offered. Most of the problems in a user-interface can be identified by extracting troubles from the verbal protocols using the model. In the trouble analysis technique, analyses of the human cognitive/thought processes, which usually requires expert knowledge and a lot of time, are not taken into consideration. Quick and easy detection of problems is first considered. The “trouble analysis” technique contributions to usability testing were empirically verified through 9 tests, employed on different kinds of products. The evaluation extent limitation, and user behavior during trouble situations, are also discussed.