• Journal of the Ergonomics Society of Korea
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• v.29 no.6
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• pp.843-851
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• 2010

This study aims to systematically develop a usability evaluation model using the Structural Equation Model (SEM) from experiment of usability on using vehicle. Vehicle developers have been adding many functions for enhance the user satisfaction. But it will be made the trade-off problem of usability and design elements of vehicle interior from attempt to make best usability satisfaction in a restricted space. To solve the trade-off problem, we set a new solution criterion from usability evaluation model. The usability experiment is based on major activity pool from derived user's acts pattern in vehicle for make more accurate usability evaluation model. And this model was built with twenty-nine measurement variables for the evaluation of usability of vehicle user. As a result, the proposed SEM model showed statistical significance as well as a high level of R Square (0.7144). This model shows the relationships of detailed usability and design elements. According to the result, this study introduces the criterion to secure the best satisfaction of usability and design elements.

• Journal of Information Technology Applications and Management
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• v.25 no.3
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• pp.17-28
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• 2018

In this paper, an activity-oriented usability model is proposed. The usability model contains two types of characteristics: special-type characteristics of usability and sub-characteristics of usability. Workability, study-ability, and playability are, but do not exhaust, examples of special-type characteristic of usability. They correspond to working, studying, and playing using the software product, respectively. They represent the goal of using and can overlap each other. They are usability too by themselves. Navigate-ability, data-prepare-ability, data-input-ability, response-wait-ability, output-examine-ability, and output-utilize-ability are typical examples of sub-characteristics of usability. They correspond to navigating, preparing data, inputting data, waiting response, examining output, and utilizing the output data, respectively. They are not usability by themselves. They constitute usability together as a group. Assessing is the fundamental and indispensable aspect of quality. Without assessing, the concept of quality has little practical value. Satisfaction, effectiveness, and efficiency are the most typical sub-characteristics of usability in existing quality models, which correspond to the evaluation criteria of usability. In the activity-oriented usability model, however, only the user's satisfaction is included: Satisfaction is regarded as the operational definition of usability in the user's view. As the result, usability can be interpreted as the 'goodness for using, which is evaluated by the user. 'Three fundamental principles regarding software quality models are proposed too in this paper: Principles of Parsimony, Cohesiveness, and Inheritance. Discussions illustrate well that typical existing usability models violate these basic principles. Many authors have tried to define general usability models which can be applied to most kinds of software. The dream of the general and universal usability model, however, may be an illusion. The activity-oriented usability model is expected to serve as a prototype from which specialized usability models can be derived.

• Journal of the Ergonomics Society of Korea
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• v.20 no.1
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• pp.45-62
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• 2001

This study suggests a genetic algorithm-based partial least squares (GA-based PLS) method to select the design variables for building a usability model. The GA-based PLS uses a genetic algorithm to minimize the root-mean-squared error of a partial least square regression model. A multiple linear regression method is applied to build a usability model that contains the variables seleded by the GA-based PLS. The performance of the usability model turned out to be generally better than that of the previous usability models using other variable selection methods such as expert rating, principal component analysis, cluster analysis, and partial least squares. Furthermore, the model performance was drastically improved by supplementing the category type variables selected by the GA-based PLS in the usability model. It is recommended that the GA-based PLS be applied to the variable selection for developing a usability model.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.30
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• pp.177-184
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• 1994

The importance of usability evaluation is increasing in developing the system(or product). Many usability measures and test methods have been developed in the fields of ergonomics and cognitive engineering. A systematic usability effort using established methods may be qualify as usability engineering. In this paper, general aspects of the usability engineering are introduced, and application methods of usability engineering model based on product's life cycle are presented.

• Proceedings of the ESK Conference
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• 1997.10a
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• pp.313-319
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• 1997

There is currently a focus on usability of interactive computer software. Previous research in software ergonomics has indicated the importance of evaluating the usability of software user interfaces. Software developers, interface designers or human foctors engineers often confront the task of comparative evaluation among systems, versions or interface designs. This study presents a structured model for comparative evaluation of user interface designs using usability criteria and measures. The proposed model consists of twomain phases : the prescreening phase ad the evaluation phase. The first phase involves expert judgment-based approach with qualitative criteria. The prescreening phase uses absolute measurement analytic hierarchy process to filter possible altermative interfaces to a reasonable subset. The second phase involves user-based approach such as usability testing, with quantitative criteria. The objective of the evaluation phase is to evaluate a subset of altermatives using objective measures. A set of criteria and measures for evaluating the usability of computer software designs is presented. The proposed model provides practitioners with a structured approach to select the best interface based on usability criteria and measures.

• Journal of Digital Convergence
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• v.11 no.5
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• pp.31-39
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• 2013

Smart TV is a television set with internet capabilities, computing ability, and broadcasting service that increases user interactions. Usability has been regarded as one of the most important criteria for measuring and evaluating smart TV. To evaluate smart TV from the perspective of usability, we first need to develop a measurement model by determining the major factors affecting usability, which become a measurement the evaluation criteria of the model. The objective of this paper is to suggest an AHP(Analytic Hierarchy Process) model for measuring usability of smart TV. Factors affecting usability are described from the prior research. We show how the judgment data is acquired and the usability score is computed by an numerical example.

• Journal of the Ergonomics Society of Korea
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• v.19 no.3
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• pp.23-37
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• 2000

Usability is one of the most important factors that affect customers' decision to purchase a product. Several studies have been conducted to model the relationship between the product design variables and the product usability. Since there could be hundreds of design variables to be considered in the model, a variable screening method is required. Traditional variable screening methods are based on expert opinions (Expert screening) in most Kansei engineering studies. Suggested in this study are statistical methods for screening important design variables by using the principal component regression(PCR), cluster analysis, and partial least squares(PLS) method. Product variables with high effect (PCR screening and PLS screening) or representative variables (Cluster screening) can be used to model the usability. Proposed variable screening methods are used to model the usability for 36 audio/visual products. The three analysis methods (PCR, Cluster, and PLS) show better model performance than the Expert screening in terms of $R^2$, the number of variables in the model, and PRESS. It is expected that these methods can be used for screening the product design variables efficiently.

• 한국경영정보학회:학술대회논문집
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• 2007.06a
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• pp.488-493
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• 2007

The main goal of this study is to propose a model of simplicity and interactivity effect on usability in the blog services. As web-based applications become increasingly complicated, the need for simplicity in user interface design has grown for better usability. Also, interactivity has been known to influence on usability. Previous studies argued that usability is a key factor for system success. Usability is concerned with attributes of an application that makes it understandable, learnable, easy to use, and attractive. For the complicated technology, perceived control, related to direct manipulation of an object, is important. In this regard, we posit that simplicity, interactivity, and perceived control makes important antecedents to usability. Finally, we tested that the effect of usability on user s loyalty with the blog services along with trust and satisfaction. Future studies will empirically examine the proposed model, emphasizing the importance of simplicity and interactivity for the user interface design.

• Journal of Distribution Science
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• v.11 no.11
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• pp.41-47
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• 2013

Purpose -This paper aims to understand how easy and convenient it is for consumers to use mobile services. A mobile service combines hardware and software with information technology. To specifically meet the needs of users of mobile applications, the context of usability was identified in consumer mobile services. Research Design, Data, and Methodology - For usability measurement and evaluation, appliances and software were the main target: this applied to an expanding range, such as a Personal Digital Assistant (PDA), mobile phones, and wired and wireless integrated services. This study extended the Technology Acceptance Model (TAM) by examining the roles of two characteristics of mobile applications'usage: usability and usefulness. Results - The study tested the research model using a structural equation modeling (SEM) technique. Results showed no significant differences between the two models. Usability comprised learnability, efficiency, memorability, errors, and satisfaction: the motivation for using a mobile application was understood as being the usefulness and easy-of-use of the mobile application. This empirical study validated the proposed research model and hypotheses, and found that the hypotheses could be supported. Finally, the phenomena derived from the causal relationships in usability were identified, and their implications considered.

• Journal of the Ergonomics Society of Korea
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• v.26 no.3
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• pp.101-109
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• 2007

This research is for developing a usability evaluation model based on customer sensation using Quality Function Deployment, which evaluates the relationship between consumer sensation and usability among the physical design factors of dishwashers. Four aspects of the evaluation model; overall sensation factors, detail sensation factors, usability evaluation factors and physical design factors of products were analyzed in three sequential processes of QFD. The sensation evaluation factors and the usability evaluation factors were created from regression analysis of the results of the sensation and usability test. Moreover, thirty-one physical design factors selected through group discussion of ergonomist and manufacturers. Among them, 19 physical design factors according to priority were applied to evaluation model using QFD. With the evaluation model using four aspects, physical design factors influencing user sensation were generated. These factors were 'alarm sound', 'dishwasher size', 'button size' and 'display size'. Consequently, the degree of influences was tested. Design guidelines for dishwashers were derived from finally generated physical design factors.