一种新的笔式交互范式的可用性评估

笔式用户界面是Post—WIMP界面的一种重要形态,具有自然、和谐的交互特性。尽管笔式用户界面广泛应用于无处不在计算环境中,但很少专门对它的可用性进行评估。针对笔式用户界面的特征,提出了一种新的笔式用户界面范式,基于此范式设计并实现了一个面向教学的笔式交互系统(PenOffice),利用此系统对范式从易学性、效率、出错率和用户满意度这几个方面进行了可用性评估,从中分析了笔式用户界面以及这种新的界面范式的优点和不足。     

Usability laboratories

This article provides a table with summary statistics for the thirteen usability laboratories described in the papers in this special issue. It also gives an introduction to the main uses of usability laboratories in usability engineering and surveys some of the issues related to practical use of user testing and CAUSE tools for computer-aided usability engineering.     

Usability laboratories

Abstract

This article provides a table with summary statistics for the thirteen usability laboratories described in the papers in this special issue. It also gives an introduction to the main uses of usability laboratories in usability engineering and surveys some of the issues related to practical use of user testing and CAUSE tools for computer-aided usability engineering.     

中看与中用——试析软件界面中可用性与美感之关系

可用性是当前评价用户界面的一个重要标准,它与用户体验相关。美感有助于营造良好的用户体验,有助于帮助用户完成任务,减轻压力,保持注意力和做出正确的决策。美观的界面更有吸引力,有助于产品的视觉识别,有助于企业创造文化价值和提升核心竞争力。设计人员有时面对着美观和功能的取舍,此时不仅应该寻找平衡更应该寻求新的更巧妙的解决方案。     

示范表演驱动的运动数据检索方法及可用性评估

以直观、自然的方式来检索运动数据可有效地提高角色动画生产效率.提出一种通过现场示范表演来检索运动数据的方法,使动画制作人员能够直观、快速地从大容量运动数据库中找到所期望的运动片段.首先通过运动传感器获取用户的示范表演,然后利用经典的DTW时序数据匹配算法来实现基于样例的运动数据检索.通过一组观察实验对它的可用性进行分析和评估的结果表明,文中方法能够显著地提升运动数据检索的效率及用户体验.     

Usability engineering laboratories: limitations and challenges toward a unifying tools/practices environment

This article discusses the limitations and challenges surrounding the present usability engineering (UE) labs. Usability laboratories include hardware and software tools to observe users, collect and analyse diverse data about the users' interactions, behaviours, actions, and reactions including their raw feedback regarding their experiences. Using statistical analysis and data mining software, these qualitative and quantitative data are transformed into design insights and recommendations for future usability improvements. First, we survey the existing stationary, portable, and remote laboratories. We then review the current usability tools while highlighting the gap between the existing tools/labs and the UE practices. We will show how this gap can be closed via a roadmap using a computer-assisted usability engineering environment (CAUTE). A CAUTE provides a unifying user interface that exploits a process-sensitive architecture for integrating the large variety of the existing tools into the best UE practices. Beyond the technical problems, there is also a need to address research issues including determining the interest of the CAUTE approach in comparison with the current usability labs.     

User Expectations in the Time of Google: Usability Testing of Federated Searching

SUMMARY

As libraries expand their services into the world of federated searching, librarians need to work with users to discover what their expectations are and how the library can customize the software to meet users' expectations. This article describes the user testing performed at Texas A&M University during 2005 as the libraries implemented a new federated search service called Search Now (ExLibris' MetaLib). Over fifty volunteers–including undergraduates, graduate students, faculty, and library faculty and staff–helped to test the new system and offered suggestions for improvements. Problems were noted and, where possible, modifications were made to improve results. These modifications were then tested again. Major issues noted during the usability testing included: user expectations of search performance; information included in and the layout of the search results; availability of advanced search options; and lack of ability to limit by format, scholarly nature of journal, date and full-text availability. Suggestions for further development are also presented.     

软件可用性教育的研究与探索

现阶段本科软件工程专业的课程体系中缺少系统性的软件可用性方面的内容,在该专业课程体系中加入可用性内容是文章讨论的主题。文章强调从用户的角度出发进行软件产品的设计和开发。主要从“研究用户”、“用户界面设计”和“可用性评估”三个方面实施教学。采用独立授课和在其主干课程中植入相关内容的教学方法。实践证明这一探索有利于全方位提高学生的素质。     

使用概率规则文法评估人机界面可用性

提出一种在界面系统设计规约的基础上使用的可用性评估方法.首先使用有限状态自动机抽象界面系统设计,根据概率规则文法对有限状态自动机的状态转换概率进行预测;然后结合用户的熟练程度提出了界面可用性评估算法;最后讨论了一个手机界面的可用性计算实例.文中方法能够在界面系统生命周期的早期使用,以较早地对不同设计方案进行比较,降低开发风险.     

The empirical investigation of Perspective-Based Reading

We consider reading techniques a fundamental means of achieving high quality software. Due to the lack of research in this area, we are experimenting with the application and comparison of various reading techniques. This paper deals with our experiences with a family of reading techniques known as Perspective-Based Reading (PBR), and its application to requirements documents. The goal of PBR is to provide operational scenarios where members of a review team read a document from a particular perspective, e.g., tester, developer, user. Our assumption is that the combination of different perspectives provides better coverage of the document, i.e., uncovers a wider range of defects, than the same number of readers using their usual technique.To test the effectiveness of PBR, we conducted a controlled experiment with professional software developers from the National Aeronautics and Space Administration/Goddard Space Flight Center (NASA/GSFC) Software Engineering Laboratory (SEL). The subjects read two types of documents, one generic in nature and the other from the NASA domain, using two reading techniques, a PBR technique and their usual technique. The results from these experiments, as well as the experimental design, are presented and analyzed. Teams applying PBR are shown to achieve significantly better coverage of documents than teams that do not apply PBR.We thoroughly discuss the threats to validity so that external replications can benefit from the lessons learned and improve the experimental design if the constraints are different from those posed by subjects borrowed from a development organization.     

Engineering the Usability of a Visual Formalism for Real-time Temporal Logic

Visual formalisms merge the rigor of mathematical notations with the naturality of graphic representation. This increases usability of formal methods, and may also improve their verification power through a richer involvement of the user. To achieve this goal, development of the visual representation must fulfill a twofold requirement: on the one hand, the design must capture the inherent rigor of the underlying formalism; on the other, it must meet the final user intuition.In this paper, we introduce, motivate and evaluate a visual formalism for a real-time logic. The visual formalism supporting presentation of the logic was designed by joining heuristic design and user-based evaluation. Heuristic principles were applied to define a limited set of visualization metaphors supporting consistent representation of basic semantic constructs. Alternative representations were defined where multiple choices were possible with no obvious expected preference. Heuristic assumptions were then refined and alternative representations were selected by resorting to the judgment of a representative sample of target end-users. The resulting notation was implemented within an interactive syntax-directed editor, which was then used to carry out a competitive user-based evaluation of the usability of textual and visual representations.     

Preventing user interface disasters

Abstract

This article defines a quantitative goal that is cheap to measure for the usability of a business application system for casual users. The article also describes a cost-effective method for attaining the goal. The goal is to eliminate all user interface disasters (UIDs) in a given system. UIDs are usability problems that seriously annoy users, or prevent them from accomplishing their work without help from a human being. The method consists of series of simple user tests without audio or video recording, and with little analysis after each user test. The article concludes by describing Baltica's results of applying the method to a medium-size business application for casual users.     

Empirical validation of an automatic usability evaluation method

Today, the success of a software application strongly depends on the usability of its interface, so the evaluation of interfaces has become a crucial aspect of software engineering. It is recognized that automatic tools for graphical user interface evaluation may greatly reduce the costs of traditional activities performed during expert evaluation or user testing in order to estimate the success probability of an application. However, automatic methods need to be empirically validated in order to prove their effectiveness with respect to the attributes they are supposed to evaluate.In this work, we empirically validate a usability evaluation method conceived to assess consistency aspects of a GUI with no need to analyze the back-end. We demonstrate the validity of the approach by means of a comparative experimental study, where four web sites and a stand-alone interactive application are analyzed and the results compared to those of a human-based usability evaluation. The analysis of the results and the statistical correlation between the tool׳s rating and humans׳ average ratings show that the proposed methodology can indeed be a useful complement to standard techniques of usability evaluation.     

Object-Oriented Function Points: An Empirical Validation

We present an empirical validation of object-oriented size estimation models. In previous work we proposed object oriented function points (OOFP), an adaptation of the function points approach to object-oriented systems. In a small pilot study, we used the OOFP method to estimate lines of code (LOC). In this paper we extend the empirical validation of OOFP substantially, using a larger data set and comparing OOFP with alternative predictors of LOC. The aim of the paper is to gain an understanding of which factors contribute to accurate size prediction for OO software, and to position OOFP within that knowledge. A cross validation approach was adopted to build and evaluate linear models where the independent variable was either a traditional OO entity (classes, methods, association, inheritance, or a combination of them) or an OOFP-related measure. Using the full OOFP process, the best size predictor achieved a normalized mean squared error of 38%. By removing function point weighting tables from the OOFP process, and carefully analyzing collected data points and developer practices, we identified several factors that influence size estimation. Our empirical evidence demonstrates that by controlling these factors size estimates could be substantially improved, decreasing the normalized mean squared error to 15%—in relative terms, a 56% reduction.     

An examination of four user-based software evaluation methods

Usability has become an important factor in the design of interactive software. In the quest to develop usable software, user participation in the design and evaluation process has been advocated. Four methods; logged data, questionnaires, interviews, and verbal protocol analyses have been the prominent base evaluation methods used, sometimes being combined in an attempt to provide a comprehensive evaluation. However, little is known about the strengths and weaknesses of these methods. In this study, these four methods were used to evaluate three different software types (spreadsheet, word processor, and database) with 148 subjects participating. The data obtained enabled a number of conclusions to be drawn regarding the usefulness of the methods when used individually and in combination.     

Facilitating energy savings with programmable thermostats: evaluation and guidelines for the thermostat user interface

Thermostats control heating and cooling in homes – representing a major part of domestic energy use – yet, poor ergonomics of these devices has thwarted efforts to reduce energy consumption. Theoretically, programmable thermostats can reduce energy by 5–15%, but in practice little to no savings compared to manual thermostats are found. Several studies have found that programmable thermostats are not installed properly, are generally misunderstood and have poor usability. After conducting a usability study of programmable thermostats, we reviewed several guidelines from ergonomics, general device usability, computer–human interfaces and building control sources. We analysed the characteristics of thermostats that enabled or hindered successfully completing tasks and in a timely manner. Subjects had higher success rates with thermostat displays with positive examples of guidelines, such as visibility of possible actions, consistency and standards, and feedback. We suggested other guidelines that seemed missing, such as navigation cues, clear hierarchy and simple decision paths.

Practitioner Summary: Our evaluation of a usability test of five residential programmable thermostats led to the development of a comprehensive set of specific guidelines for thermostat design including visibility of possible actions, consistency, standards, simple decision paths and clear hierarchy. Improving the usability of thermostats may facilitate energy savings.     

An Empirical Study of Use Contexts in the Mobile Internet,Focusing on the Usability of Information Architecture

The mobile Internet—accessing the Internet via a mobile device—has become quite popular recently. The mobile Internet is mainly different from the stationary Internet because it may be used in various contexts, whereas the stationary Internet is mostly used in pre-determined environments. However, it is unclear when the mobile Internet is used most frequently, and in what context it is most useful. A greater understanding of the contexts for using the mobile Internet will relieve usability problems that mobile Internet users often encounter.This paper proposes a conceptual framework of use contexts, which includes various facets of contexts related to the mobile Internet. It then presents the results of an exploratory study in which the use contexts for the mobile Internet and corresponding usability problems have been empirically monitored. The results indicate that use of the mobile Internet is heavily clustered around a few key contexts, rather than dispersed widely in diverse contexts. Moreover, different contexts are found to cause different kinds of usability problems. The paper ends with theoretical and practical implications of the study results.