浅谈可用性的GUI设计

GUI设计已成为软件设计中最为重要的部分之一。本文阐述了GUI在设计上的发展及其趋势,并以提升可用性为目的对GUI设计的基本要素进行了分析。     

Information system professionals’ knowledge and application gaps toward Web design guidelines

Web design guidelines are adopted by many usability evaluation methods as one of the criteria for success, while usability is proven to significantly impact Website performance. Since Web design guidelines cover a broad range of system and interface design solutions, knowledge of them can be considered as a prominent indicator of Web design skills for information systems (IS) professionals. This study empirically assessed how much IS professionals know and apply Web design guidelines via a survey to 500 randomly selected companies from Taiwan’s Fortune 2000 corporations. As expected, the knowledge–application gaps of IS professionals were statistically significant in all Web design guideline categories. Meanwhile, certain guideline categories were proven to be more difficult to acquire or apply than others. Finally, degree, gender, experience, training hours, and courses taken were also proven to be determining factors for Web design guideline skills. Implications for developing Web design guideline skills are also discussed.     

Increasing usability when interacting through screen readers

The application of appropriate Web site design and evaluation methods helps to ensure more usable and accessible Web sites. While in the literature guidelines and evaluation methods for accessibility and usability are given and discussed separately, we aim at identifying the relationships between these two concepts, in particular considering usability criteria for accessible Web sites. In this work, we propose a set of such criteria targeted to improving the navigability for a specific group of disabled users, i.e., vision-impaired people. The identification of the eighteen criteria suggested herein was performed through empirical feedback, by which potential issues were identified. Subsequently, a systematic method was developed on the basis of the analysis of potential solutions, resulting in a classification of the criteria according to usability aspects. Some example applications of the proposed criteria to three existing public administration Web sites are discussed.     

Web课程的可用性研究

提高Web课程的可用性可以增强课程的学习效果。文章提出了Web课程可用性应考虑的三个方面：课程界面设计、课程内容设计和课程站点设计，并从实际设计中分析了实现Web课程可用性的指导原则，提出了改进Web课程可用性的具体措施和方法。     

Usability testing — on a budget: a NASA usability test case study

Okay, so you've purchased a graphical user interface (GUI) builder tool to help you quickly build a sophisticated user interface, and your developers promise to follow a particular style guide (e.g., OSF/Motif, Apple/Macintosh) when creating the GUI. This is definitely a step in the right direction, but it is no guarantee that the application's user interface will be usable; that is, where the user interface helps, rather than hinders, the end-users from doing their jobs. Numerous techniques for testing the usability and user satisfaction of an application's GUI are available, such as design walk-throughs, field testing with beta releases, demonstrations of prototypes to future end-users, and user questionnaires. One of the most effective techniques is usability testing with defined tasks and metrics, and yet, it is not commonly used in project development life cycles at the National Aeronautics and Space Agency (NASA). This paper discusses a low-budget, but effective, approach we used at NASA's Goddard Space Flight Center (GSFC) to perform structured usability testing. It did not require any additional staff or a usability laboratory, but did successfully identify problems with the application's user interface. The purpose of the usability testing was two-fold: (1) to test the process used in the usability test; and (2) to apply the results of the test to improving the subject software's user interface. This paper will discuss the results from the test and the lessons learned. It will conclude with a discussion of future plans to conduct cost benefit analysis and integrate usability testing as a required step in a project's development life cycle.     

The impact of visual layout factors on performance in Web pages: a cross-language study

Visual layout has a strong impact on performance and is a critical factor in the design of graphical user interfaces (GUIs) and Web pages. Many design guidelines employed in Web page design were inherited from human performance literature and GUI design studies and practices. However, few studies have investigated the more specific patterns of performance with Web pages that may reflect some differences between Web page and GUI design. We investigated interactions among four visual layout factors in Web page design (quantity of links, alignment, grouping indications, and density) in two experiments: one with pages in Hebrew, entailing right-to-left reading, and the other with English pages, entailing left-to-right reading. Some performance patterns (measured by search times and eye movements) were similar between languages. Performance was particularly poor in pages with many links and variable densities, but it improved with the presence of uniform density. Alignment was not shown to be a performance-enhancing factor. The findings are discussed in terms of the similarities and differences in the impact of layout factors between GUIs and Web pages. Actual or potential applications of this research include specific guidelines for Web page design.     

Usability testing — on a budget: a NASA usability test case study

Abstract

Okay, so you've purchased a graphical user interface (GUI) builder tool to help you quickly build a sophisticated user interface, and your developers promise to follow a particular style guide (e.g., OSF/Motif, Apple/Macintosh) when creating the GUI. This is definitely a step in the right direction, but it is no guarantee that the application's user interface will be usable; that is, where the user interface helps, rather than hinders, the end-users from doing their jobs. Numerous techniques for testing the usability and user satisfaction of an application's GUI are available, such as design walk-throughs, field testing with beta releases, demonstrations of prototypes to future end-users, and user questionnaires. One of the most effective techniques is usability testing with defined tasks and metrics, and yet, it is not commonly used in project development life cycles at the National Aeronautics and Space Agency (NASA). This paper discusses a low-budget, but effective, approach we used at NASA's Goddard Space Flight Center (GSFC) to perform structured usability testing. It did not require any additional staff or a usability laboratory, but did successfully identify problems with the application's user interface. The purpose of the usability testing was two-fold: (1) to test the process used in the usability test; and (2) to apply the results of the test to improving the subject software's user interface. This paper will discuss the results from the test and the lessons learned. It will conclude with a discussion of future plans to conduct cost benefit analysis and integrate usability testing as a required step in a project's development life cycle.     

Reconfigurable simulator using graphical user interface (GUI) and object-oriented design for OFDM systems

In this paper, a design of a new object-oriented simulation environment and graphical user interface (GUI) for versatile orthogonal frequency division multiplexing (OFDM) systems is presented. This is achieved using high-level design, parallelism and usability for the simulation environment. GUI interface can serve as a learning/research tool for students or practiced professionals to investigate particular designs. It is evident that OFDM systems intended to be used in dynamic environments must be tested under various conditions in order to be designed for optimality. Hence, a simulation design is proposed coupling the GUI, parallelism, and high-level object-oriented design techniques to be beneficial to the researcher. A high-level design and GUI layouts of the proposed simulator is shown in details. Important OFDM parameters needed for reconfiguration of transmitter components, channel condition parameters, and receiver components are discussed. In addition, this paper provides a simple technique to implement simulation partitioning for increased parallel performance of reconfigurable object-oriented OFDM simulators. This simple technique applies to scenarios where there is disproportionate simulation duration between different OFDM configurations. It is shown to decrease total simulation time considerably.     

基于Qt/Embedded的Web浏览器的设计与实现

介绍基于Qt/Embedded设计的Web浏览器和嵌入式Linux GUI的发展概况,简单描述Qt/Embedded的平台搭建,重点介绍嵌入式Web浏览器的设计原则及基于Qt/Embedded的Web浏览器的开发过程。     

网络电视机顶盒GUI系统的设计与实现

网络电视机顶盒（Web TV Set Top Box)是一种典型的嵌入式应用，其人机交互界面和Web浏览器等应用均需要GUI系统的支持。本文提出了一个网络电视机顶盒GUI系统的设计方案，并详细阐述了其中最重要的两部分－驱动程序与窗口系统的具体实现，本GUI系统结构简单，占用资源少，可靠性高，配置灵活，具有良好的可移植性，该系统已推广应用，满足了应用要求。     

Reflecting on the Design Process for Virtual Reality Applications

A reflective analysis on the experience of virtual environment (VE) design is presented focusing on the human–computer interaction (HCI) challenges presented by virtual reality (VR). HCI design guidelines were applied to development of two VRs, one in marine archaeology and the other in situation awareness simulation experiments. The impact of methods and HCI knowledge on the VR design process is analyzed, leading to proposals for presenting HCI and cognitive knowledge in the context of design trade-offs in the choice of VR design techniques. Problems reconciling VE and standard Graphical User Interface (GUI) design components are investigated. A trade-off framework for design options set against criteria for usability, efficient operation, realism, and presence is proposed. HCI-VR design advice and proposals for further research aimed towards improving human factor-related design in VEs are discussed.     

Impacts of navigation structure,task complexity,and users’ domain knowledge on Web site usability—an empirical study

It is essential for designers of Web sites to understand what navigation structure results in better usability for knowledge acquisition tasks of varying complexity and the Web site users with different level of domain knowledge. Literature shows that multiple factors may exert influence on Web site usability. Navigation structure, task complexity, and user domain knowledge level are among of those factors. Hypotheses are developed about the usability of alternative navigation structures, with different task complexity and user domain knowledge level. Experiments are designed and conducted to test these hypotheses in terms of user performance (accuracy, speed) in accomplishing sets of simple and comparatively complex knowledge acquisition tasks. User perceptions of usability are also measured. Two rounds of experimentation are performed, one with participants who have been trained in the domain of production and operations management, the other with participants who have not been trained in this domain. The results show that a usage-oriented hierarchy or a combined hierarchy are navigation structures associated with statistically significantly higher performance usability than a subject-oriented hierarchy, for both simple and relatively complex knowledge acquisition task sets. A statistically significant effect of domain knowledge on the perception aspect of usability is identified. The study contributes to enhancing the comprehension of researchers, practitioners, and educators about design and usability of Web site navigation structures.     

Usability evaluation methods for the web: A systematic mapping study

Context

In recent years, many usability evaluation methods (UEMs) have been employed to evaluate Web applications. However, many of these applications still do not meet most customers’ usability expectations and many companies have folded as a result of not considering Web usability issues. No studies currently exist with regard to either the use of usability evaluation methods for the Web or the benefits they bring.

Objective

The objective of this paper is to summarize the current knowledge that is available as regards the usability evaluation methods (UEMs) that have been employed to evaluate Web applications over the last 14 years.

Method

A systematic mapping study was performed to assess the UEMs that have been used by researchers to evaluate Web applications and their relation to the Web development process. Systematic mapping studies are useful for categorizing and summarizing the existing information concerning a research question in an unbiased manner.

Results

The results show that around 39% of the papers reviewed reported the use of evaluation methods that had been specifically crafted for the Web. The results also show that the type of method most widely used was that of User Testing. The results identify several research gaps, such as the fact that around 90% of the studies applied evaluations during the implementation phase of the Web application development, which is the most costly phase in which to perform changes. A list of the UEMs that were found is also provided in order to guide novice usability practitioners.

Conclusions

From an initial set of 2703 papers, a total of 206 research papers were selected for the mapping study. The results obtained allowed us to reach conclusions concerning the state-of-the-art of UEMs for evaluating Web applications. This allowed us to identify several research gaps, which subsequently provided us with a framework in which new research activities can be more appropriately positioned, and from which useful information for novice usability practitioners can be extracted.     

Improving Web usability through visualization

One reason for poor Web site usability is researchers' lack of understanding about how users surf for information. Predictive Web usage visualizations can help analysts uncover traffic patterns and usability problems. The author describes some of the techniques those in the User Interface Research Group at PARC have developed to visualize content changes, linkage structures, site usage, and so on. He explores how these techniques can be used to identify specific usability problems at large Web sites. As part of his work, he have created a predictive visualization model called Information Scent, in which simulated users help uncover patterns and deficiencies in information accessibility. He demonstrates these techniques using a prototype system called ScentViz to illustrate how Web usage analysis can be enhanced using visualization methods     

Objects and the Web

Good design practices are increasingly important in Web development. The authors apply such practices using a framework for layered architectures based on the Smalltalk GUI development pattern of model-view-controller     

The contribution of apparent and inherent usability to a user's satisfaction in a searching and browsing task on the Web

Previous research found that apparent and inherent usability had big influences on user's acceptance of computer systems. This research extended these findings to the area of user's satisfaction. The study investigated the impact of inherent and apparent usability on user's satisfaction of Web page designs while the two main tasks on the World Wide Web, searching and browsing, were performed. The results indicated that inherent usability was the main factor contributing to user's satisfaction in both searching and browsing. General principles and specific recommendations for the design and evaluation of Web page designs are derived from these findings.     

图形人机接口的形式化描述

本文讨论了人机接口的分类及特点，着重介绍了图形人机接口的重要性及实用性；引入了回溯自动机作为定义人机接口的一种抽象数学模型，并采用该模型给出其图形人机接口的形式化描述。     

基于AJAX的富客户端技术及应用

AJAX即异步的JavaScript与XML,利用JavaScript、HTML、DOM技术进行Web富客户端设计,后台异步执行与服务器的交互,不会因为交互而中断用户对屏幕的操作,可提供更好的服务响应。AJAX使得基于Web的传统客户端设计,达到与单机GUI方式同样的效果,对基于Web的分布式系统设计产生了重要影响。通过与传统的Web开发方式进行对比,详细介绍了AJAX的核心技术和使用AJAX开发Web应用系统的基本原理。     

A framework for evaluating the usability of mobile phones based on multi-level, hierarchical model of usability factors

As a mobile phone has various advanced functionalities or features, usability issues are increasingly challenging. Due to the particular characteristics of a mobile phone, typical usability evaluation methods and heuristics, most of which are relevant to a software system, might not effectively be applied to a mobile phone. Another point to consider is that usability evaluation activities should help designers find usability problems easily and produce better design solutions. To support usability practitioners of the mobile phone industry, we propose a framework for evaluating the usability of a mobile phone, based on a multi-level, hierarchical model of usability factors, in an analytic way. The model was developed on the basis of a set of collected usability problems and our previous study on a conceptual framework for identifying usability impact factors. It has multi-abstraction levels, each of which considers the usability of a mobile phone from a particular perspective. As there are goal-means relationships between adjacent levels, a range of usability issues can be interpreted in a holistic as well as diagnostic way. Another advantage is that it supports two different types of evaluation approaches: task-based and interface-based. To support both evaluation approaches, we developed four sets of checklists, each of which is concerned, respectively, with task-based evaluation and three different interface types: Logical User Interface (LUI), Physical User Interface (PUI) and Graphical User Interface (GUI). The proposed framework specifies an approach to quantifying usability so that several usability aspects are collectively measured to give a single score with the use of the checklists. A small case study was conducted in order to examine the applicability of the framework and to identify the aspects of the framework to be improved. It showed that it could be a useful tool for evaluating the usability of a mobile phone. Based on the case study, we improved the framework in order that usability practitioners can use it more easily and consistently.     

The Relative Importance of Usability and Functionality Factors for E‐Health Web Sites

With the growing usage of the Internet, the demand for online health care information and advice as well as the number of health‐related Web sites are increasing. In case of online health information and advice, the user interface replaces face‐to‐face communication. To ensure that the users' needs are met, it is critical to balance functionality and usability in the design of the Web site. The present study seeks to identify the complex interrelationships among the various factors of usability and functionality concerning e‐health Web sites. Two Turkish e‐health Web sites were assessed for evaluation in this study. The findings show that the users of the health information Web sites give a higher priority to functionality and its factors, whereby the highest relative importance is on “services/facilities” and “personalization/categorization of information.” The most important usability factors related to the e‐health Web sites are “memorability” and “interaction.” © 2012 Wiley Periodicals, Inc.