Teruya Ikegami

Development of Quantitative Usability Evaluation Method

A variety of evaluation methods are practiced in order to make more appealing and improve the usability of computer systems. The authors have developed a quantitative usability evaluation method that uses a checklist that outlines an evaluation procedure and clarifies judging standards. This paper describes this quantitative usability evaluation method that is not influenced by an evaluators subjective impression. Moreover, such clear and precise definitions makes checklist-based evaluations more repeatable (thus more reliable) and less affected by differences among evaluators. The effectiveness of our checklist has been evaluated by the experiments with novice and experienced evaluators. This article reports the method and results of the experiments.

Quantifying Visual Attention—Modeling Effects of Object Size

In order to develop a visual attention model for quantifying effects of object size, we made a hypothesis that the visual attention by object size of rectangle can be quantified by the width and height of object. To verify the hypothesis, we carried out an experiment with 18 participants. As a result of the experiment, we found that width, height, and interaction between them are effective factors for quantifying the visual attention by object size. From the comparison of estimation accuracy with the existing model based on pixel level position, we found that the proposed model based on the width and height of object has an equivalent estimation accuracy to the existing model. We concluded therefore that the visual attention by object size of a rectangle can be quantified by the width and height of object.

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.

InfoCruise: Information Navigation Presenting a Focus Facet Based on Context

In order to find desired information on mobile phones, it is necessary to set search keywords easily and to explore a search if a users information needs are not well defined. We propose an information navigation method to help users succeed in finding information on mobiles. Our proposal method presents to users a focus facet by analyzing context about contents, users and dialog. The focus facet is presented each time users refine a search. Users can select their desired keyword from the facet, and check the search results, and then users can define their ambiguous needs through interaction. We evaluated our method compared to a traditional search method. In our experiments, a users load for setting some keywords of our method is lower than the traditional search method. Users can experience greater search success and satisfaction using our method than the traditional search method.

An adaptive web browsing method for various terminals: a semantic over-viewing method

This paper proposed a semantic over-viewing method. This method extracts headings and semantic blocks by analyzing a layout structure of a web page and can provide a semantic overview of the web page. This method allows users grasp the overall structure of pages. It also reduces the number of operations to target information to about 6% by moving along semantic blocks. Additionally, it reduces the cost of Web page creation because of adapting one Web page content to multi-terminals. The evaluations were conducted in respect to effectiveness, efficiency and satisfaction. The results confirmed that the proposed browser is more usable than the traditional method.