Axiomatic evaluation method and content structure for information appliances

Yinni Guo, Purdue University

Abstract

Extensive studies have been conducted to determine how best to present information in order to enhance usability, but not what information is needed to be presented for effective decision making. Hence, this dissertation addresses the factor structure of the nature of information needed for presentation and proposes a more effective method than currently available ones to identify usability problems. To this end, first, 375 participants completed a paper-based survey of 68 items. The objective of the questionnaire was to examine the essential information needed for information appliances as well as the factor structure of this information. The construct validity of the questionnaire was established by data from the background literature. The following nine factors of content preparation for information appliances were derived: information of input and search, information of functions, information of operation, information of multimedia functions, information of stored files, information of phone calls, help and service information, information of accessorial functions, and information of message. Based on the theory of Axiomatic Design, a new method of usability was developed and validated on three products (music player, digital camera and cell phone). The Axiomatic Evaluation method investigates not only the usability problems reported by the participants, but also customer requirements and control usability problems through checking the mapping matrix between three domains (customer domain, functional domain, control domain). An experiment was designed to compare this new method with a widely used usability evaluation method, the Think Aloud method. 60 people were recruited for both the control group, which used the Think Aloud method, and the experimental group, which used the Axiomatic Evaluation method. For the cell phone, a complex information appliance, the Axiomatic Evaluation method detected 113% more usability problems than the Think Aloud method. However, for the music player and digital camera, which are simpler information appliances, the Axiomatic Evaluation method was not useful. This lack of usefulness for the latter products was because they contained more straightforward usability problems that could also be found by the Think Aloud method. The usability problems identified by the two groups were evaluated for their importance by 30 Information Technology experts. The results revealed that, for the cell phone, the problems found by Axiomatic Evaluation method had a higher importance score than the problems found by Think Aloud method. Theoretical contributions of this study include extension of the application domain for Axiomatic Design theory and development of an effective Axiomatic Evaluation method for usability evaluation. Practical contributions include guidelines for content design for information appliances and validation of the Axiomatic Evaluation method for complex information appliances.

Degree

Ph.D.

Advisors

Proctor, Purdue University.

Subject Area

Information Technology|Industrial engineering

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