Myung Hwan Yun

A Usability Checklist for the Usability Evaluation of Mobile Phone User Interface

In the last decade, the research of the usability of mobile phones has been a newly evolving area with few established methodologies and realistic practices that ensure capturing usability in evaluation. Thus, there exists growing demand to explore appropriate evaluation methodologies that evaluate the usability of mobile phones quickly as well as comprehensively. This study aims to develop a task-based usability checklist based on heuristic evaluations in views of mobile phone user interface (UI) practitioners. A hierarchical structure of UI design elements and usability principles related to mobile phones were developed and then utilized to develop the checklist. To demonstrate the practical effectiveness of the proposed checklist, comparative experiments were conducted on the usability checklist and usability testing. The majority of usability problems found by usability testing and additional problems were discovered by the proposed checklist. It is expected that the usability checklist proposed in this study could be used quickly and efficiently by usability practitioners to evaluate the mobile phone UI in the middle of the mobile phone development process.

Incorporating user satisfaction into the look-and-feel of mobile phone design

The look-and-feel of the mobile phone was investigated using a consumer survey. Seventy-eight participants evaluated the design of 50 different mobile telephones on the perceived scale of image/impression characteristics, including: luxuriousness, simplicity, attractiveness, colourfulness, texture, delicacy, harmoniousness, salience, rigidity, and overall satisfaction. Stepwise multiple linear regression analysis were used to evaluate results. The results showed that the image and impression characteristics of the products were closely related to the human-product interface specifications as well as overall shape of the product. Design variables such as texture, use of surface curvature, surface treatment, operating sound, and control response ratio were perceived as important by customers. This study also suggested a series of statistical processes for selecting and screening the critical design variables closely related to the customers impression of a product. The product evaluation and analysis methods could be generalized to other consumer products.

Enhancing the Minority Discipline in the IT Industry: A Survey of Usability and User-Centered Design Practice

This article reports the results of a survey conducted in 2003 of 184 information technology (IT) development practitioners and 90 user interface (UI)/usability practitioners. The survey covered a broad range of issues including the respondents profiles, current development environment, usability and user-centered design (UCD) adoption issues in Korean IT development environments, overall assessment of UCD/usability, and the most widely used methods and techniques. The results reveal various UCD/usability practices and problems in the IT industry. For both development practitioners and UI/usability practitioners, the most serious problems encountered in a project are the differences between output and customer requirements, as well as further requirements from customer, delays in a project schedule, and overages on project budgets. The degree of recognition of usability/UCD is higher than expected, but UCD/usability is not yet fully employed in the project, because 42% of respondents used usability/UCD. Profiles from UI/usability practitioners and projects show a relatively weak position and short HCI tradition in the Korean IT industry. This study is expected to provide both an empirical basis for usability and UCD planning, training, adoption, and execution in the IT industry of Korea and an important information source for many HCI practitioners outside Europe and the United States who struggle to introduce usability into their IT industries.

A User-Centered Approach for Ubiquitous Service Evaluation: An Evaluation Metrics Focused on Human-System Interaction Capability

As the ubiquitous era took off, the interactions between ubiquitous services and users have come to take an important position. So it is necessary to develop new evaluation method that evaluates interactivity with a user-centered perspective. The main objective of this study is the development of user-centered interactivity evaluation metrics of ubiquitous service attributes. For this objective, first, existing ubiquitous service evaluation methodologies are reviewed to define the evaluation attributes for ubiquitous service evaluation. Second, user oriented interactive metrics that can overcome the limitations of those service evaluation methodologies, such as personal service evaluation techniques, usability evaluation techniques and psychometrics based evaluation techniques, are developed. As a validation study, suggested evaluation metrics is utilized to evaluate the u-home service, and priority of each metrics is derived. The suggested evaluation metrics can be used to evaluate the interactivity level of ubiquitous service and identify the potential users and their requirements at the stage of service development.

Classification of bluffing behavior and affective attitude from prefrontal surface encephalogram during on-line game

The purpose of this research was to detect the pattern of player’s emotional change during on-line game. By defining data processing technique and analysis method for bio-physiological activity and player’s bluffing behavior, the classification of affective attitudes during on-line game was attempted. Bluffing behavior displayed during the game was classified into two dimensions of emotional axis based on prefrontal surface electroencephalographic data. Classified bluffing attitudes were: (1) pleasantness/unpleasantness; and (2) honesty/bluffing. A multilayer-perception neural network was used to classify the player state into four attitude categories. Resulting classifier showed moderate performance with 67.03% pleasantness/unpleasantness classification, and 77.51% for honesty/bluffing. The classifier model developed in this study was integrated to on-line game as a form of ‘emoticon’ which displays facial expression of opposing player’s emotional state.

Selection and Classification of the Usability Attributes for Evaluating Consumer Electronic Products

Although the concept of usability has been well defined in the software usability engineering area, it is not appropriate to apply the same concept directly to the consumer electronic products. A new concept of usability appropriate for evaluating consumer electronic products was suggested in this study. It is characterized by integrating both the performance and impression factors. Based on the concept developed, specific usability attributes were defined and classified. In addition, the usability measures along with appropriate measurement techniques were also developed and classified to evaluate the usability attributes in an efficient and systematic manner. The results of this study can be used to evaluate the usability of consumer electronic products.

A statistical model of relationship between affective responses and product design attributes for capturing user needs

Customers satisfaction is a critical factor to a products success and identifying key affective response factors which customers mainly perceive is critical to satisfy customers. This study aims to identify the key affective response factor of satisfaction for passenger car interior material using statistical approach. Related variables of satisfaction consisting of 10 affective response variables associated with look-and-feel and touch feel of a surface material was systematically identified through literature survey, customer reviews, and expert opinions. Thirty participants evaluated 41 different crash pad samples using a questionnaire survey with 9-point semantic differential scale and 100-point scale. Based on the survey results, softness was identified as the key affective response factor of satisfaction for car crash pad. Then the relationship between softness and related engineering variables was identified. It is expected that the results could suggest the optimal combination and provide specific design guidelines quantitatively.

A systematic procedure for modeling usability based on product design variables: a case study in audiovisual consumer electronic products.

A systematic modeling approach to describing, prescribing, and predicting usability of a product has been presented. Given the evaluation results of the usability dimension (UD) and the measurement of the product’s design variables, referred to as the human interface elements (HIEs), the approach enables one to systematically assess the relationship between the UD and HIEs. The assessed relationship is called a usability model. Once built, such a usability model can relate, in a quantitative manner, the HIEs directly to the UDs, and thus can serve as an effective aid to designers by evaluating and predicting the usability of an existing or hypothetical product. A usability model for elegance of audiovisual consumer electronic products has been demonstrated.

An evaluation framework for the design concepts of tangible interface on new collaborative work support system

This study aims to suggest a systematic evaluation framework to evaluate design concepts of a new product at the conceptual design phase based on users requirements and tasks, development trends of relevant technologies, and the CPV. The proposed framework to evaluate design concepts of a new product consists of three phases. In phase 1, we identify and analyze users needs, functional requirements and their expected tasks by utilizing user scenario-based analysis and hierarchical task analysis. In phase 2, by deploying a relevant technology roadmap, we investigate technology alternatives for satisfying the user needs or functional requirements. In phase 3, we evaluate the design concepts using evaluation checklist, which is based on functional requirements derived from relationships analysis, utilizing CPV attribute for a quantifiable measure. A case study was demonstrated to evaluate the design concepts of a new CSCW-based tangible interface that was recently designed to support group decision making activities.

Measuring Customer Perceptions on Product Usability: Development of Image and Impression Attributes of Consumer Electronic Products

The image and impression characteristics of the typical home electronic products were investigated by a consumer survey. A total of 60 subjects evaluated 36 audio/video electronic products on 25 different image attributes such as conceptual image, luxuriousness, color perception and magnificence. The result was compared with 52 design variables predetermined to be related to the customers perception of the product. The results showed that the image and impression characteristics of the products are closely related to the human interface specifications as well as the overall dimension of the products. Design variables such as texture, use of surface curvature, surface treatment, operating sound, and control response ratio were perceived as important by the customers. This study also suggested a series of statistical process for selecting and screening the critical design variables that are closely related to the customers impression of a product.