可信路径的设计与实现

可信路径为用户提供一种途径来鉴别系统,确认所交互的系统没有被篡改,从而防止特洛伊木马之类的恶意代码窃取口令或截取会话。本论针对Unix类操作系统提出了一种可信路径的完整设计,它包括可信登录和可信会话两部分,每一部分又分为控制台界面和图形界面两种情形。本文还从可信路径角度把系统划分为四个状态,并描述了它们之间的转换关系,而安全注意键则是导致状态转换的操作。基于这些转换关系可以更加容易把设计映射到实际的系统。最后,基于FreeBSD操作系统实现了安全注意键以唤醒用户与系统之间的可信路径。通过可信路径,FreeBSD能够为用户提供一个更加安全的操作环境。     

Designing Triggers with Trigger-By-Example

One of the obstacles that hinder database trigger systems from their wide deployment is the lack of tools that aid users in creating trigger rules. Similar to understanding and specifying database queries in SQL3, it is difficult to visualize the meaning of trigger rules. Furthermore, it is even more difficult to write trigger rules using such text-based trigger rule languages as SQL3. In this paper, we propose TBE (Trigger-By-Example) to remedy such problems in writing trigger rules visually by using QBE (Query-By-Example) ideas. TBE is a visual trigger rule composition system that helps the users understand and specify active database triggers. TBE retains benefits of QBE while extending features to support triggers. Hence, TBE is a useful tool for novice users to create simple triggers in a visual and intuitive manner. Further, since TBE is designed to hide the details of underlying trigger systems from users, it can be used as a universal trigger interface.     

Tele-Graffiti: A Camera-Projector Based Remote Sketching System with Hand-Based User Interface and Automatic Session Summarization

One way to build a remote sketching system is to use a video camera to image what each user draws at their site, transmit the video to the other sites, and display it there using an LCD projector. Such camera-projector based remote sketching systems date back to Paul Wellner's (largely unimplemented) Xerox Double DigitalDesk. To make such a system usable, however, the users have to be able to move the paper on which they are drawing, they have to be able to interact with the system using a convenient interface, and sketching sessions must be stored in a compact format so that they can be replayed later. We have recently developed Tele-Graffiti, a remote sketching system with the following three features: (1) real-time paper tracking to allow the users to move their paper during system operation, (2) a hand based user interface, and (3) automatic session summarization and playback. In this paper, we describe the design, implementation, and performance of Tele-Graffiti.Supplementary material to this paper is available in electronic form at http://dx.doi.org/10.1023/A:1023084706295     

User preferences for adaptive user interfaces in health information systems

An adaptive user interface requires identification of user requirements. Interface designers and engineers must understand end-user interaction with the system to improve user interface design. A combination of interviews and observations is applied for user requirement analysis in health information systems (HIS). Then, user preferences are categorized in this paper as either data entry, language and vocabulary, information presentation, or help, warning and feedback. The user preferences in these categories were evaluated using the focus group method. Focus group sessions with different types of HIS users comprising medical staff (with and without computer skills) and system administrators identified each user group’s preference for the initial adaptation of the HIS user interface. User needs and requirements must be identified to adapt the interface to users during data entry into the system. System designers must understand user interactions with the system to identify their needs and preferences. Without this, interface design cannot be adapted to users and users will not be comfortable using the system and eventually abandon its use.     

Integrated systems II: Multi-tier interfaces for integrating families of systems

Of critical importance is the design of the man-machine interfaces for general rule based systems. They must serve (i) as user-friendly interfaces for different classes of users for different applications and (ii) to invoke service components in integrated packages without interrogating users. These objectives are achieved with a multitier interface design whose two parts, the Interactive User-Friendly Interface (IUFI) and the System Interface (SI), communicate with each other via commonly used notational systems and can be invoked independently of each other. The user-friendly interface, which is uniquely designed for each user discipline, passes information to the SI. The SI does not change for new IUFI designs and it can be invoked by other rule based systems without interrogating users.Here the requirements for the IUFI and SI parts are identified, four different designs of multi-tier interfaces are given and two applications are described. Also included are guidelines for designing user friendly interfaces.     

Elderly user experience to improve a Kinect-based game playability

When it comes to using computers, older people experience many barriers, which are a considerable hurdle to overcome in order to enable them to accept technological aids. Thus, computer interface design and development must support elderly end users by avoiding many usability issues which lead to negative impacts on them. This paper describes the combination of a computer game design for the elderly and its implementation with user experience considerations embedded in the process. In this way, a positive gaming experience is provided to the end user. This game uses the Kinect device, enabling users to interact intuitively with the computer without any intermediary controller, and its main purpose is to promote at the same time cognitive and physical activities for healthy living. Feedback was taken from physiotherapists’ written observations and user experience questionnaires, which allowed the game to be adapted to their needs, obtaining 86.25% satisfaction. The effectiveness of this study opens the door to new developments in ICT that not only improve quality of life but also reduce the existing digital divide for the elderly.     

A metapattern-based automated discovery loop for integrated datamining-unsupervised learning of relational patterns

A metapattern (also known as a metaquery) is a new approach for integrated data mining systems. As opposed to a typical “toolbox”-like integration, where components must be picked and chosen by users without much help, metapatterns provide a common representation for inter-component communication as well as a human interface for hypothesis development and search control. One weakness of this approach, however, is that the task of generating fruitful metapatterns is still a heavy burden for human users. In this paper, we describe a metapattern generator and an integrated discovery loop that can automatically generate metapatterns. Experiments in both artificial and real-world databases have shown that this new system goes beyond the existing machine learning technologies, and can discover relational patterns without requiring humans to pre-label the data as positive or negative examples for some given target concepts. With this technology, future data mining systems could discover high-quality, human-comprehensible knowledge in a much more efficient and focused manner, and data mining could be managed easily by both expert and less-expert users     

Increasing usability of voice activated dialing systems

Research suggests that cellular phone use while driving increases the risk of an auto accident by a factor of 4. Additionally, it has yet to be shown that hands-free phones (such as those which use voice-activated dialing systems (VADS)) provide any added safety benefit over manual phones. Since it has been shown that driving performance is degraded during complex conversations especially under demanding driving conditions it makes sense to design the VADS interface to be as intuitive and simple to navigate as possible in order to reduce the risk of an accident. This paper presents the results of an investigation of a commercially available voice-activated dialing system under simulated driving conditions and provides recommendations for improvement of its call flows and user-interface design. Considering the call flow findings, we conclude that the voice phone book metaphor provides an adequate mental map which helps users navigate the menu hierarchy with some minor exceptions. With regard to the user interface design findings, we conclude that any VADS could be improved by following the principles of conversational speech such as avoiding repetition and being flexible in its handling of interruptions.

Relevance to industry

The design of a VADS interface should be as intuitive and simple to navigate as possible. This study suggests recommendations to improve both the call flow structure and user interface design of a commercially available VADS.     

Information appliances and tools in Visage

A workspace for information analysis must support two types of analysis: routine information reporting and exploratory analysis. We have been developing a workspace called Visage to address both types of analysis tasks. Our goal is for expert users to move easily between routine tasks and exploratory data analysis as situations demand. Furthermore, recognizing the inherent complexity of data analysis, we want a system that is accessible to occasional users yet simultaneously provides power and flexibility for expert users. Ideally, such a system should support a gradual shift to increasing expertise so that occasional users of routine interfaces can perform more detailed analyses if needed. Visage addresses these needs by providing a consistent interface to a wide variety of data manipulation and visualization primitives. Plus, it lets users combine these operations to create appliances-special-purpose applications capturing multiple steps of a routine data analysis process-in a single, simple interface. Analysts thus benefit from a common set of operations and ways to integrate information across applications. Visage provides both basic tools and specialized information appliances to help them     

A Listening Keyboard for Users with Motor Impairments—A Usability Study

Computer users with motor impairments find it difficult and, in many cases, impossible to access PC functionality through the physical keyboard-and-mouse interface. Studies show that even able-bodied users experience similar difficulties when interacting with mobile devices; this is due to the reduced size/usability of the input interfaces. Advances in speech recognition have made it possible to design speech interfaces for alphanumeric data entry and indirect manipulation (cursor control). Although several related commercial applications exist, such systems do not provide a complete solution for arbitrary keyboard and mouse access, such as the access needed for, say, typing, compiling, and executing a C++ program.We carried out a usability study to support the development of a speech user interface for arbitrary keyboard access and mouse control. The study showed that speech interaction with an ideal listening keyboard is better for users with motor impairments than handstick, in terms of task completion time (37% better), typing rate (74% better), and error rates (63% better). We believe that these results apply to both permanent and task-induced motor impairments. In particular, a follow-up experiment showed that handstick approximates conventional modes of alphanumeric input available on mobile devices (e.g., PDAs, cellular phones, and personal organizers). These modes of input include miniaturized keyboards, stylus soft keyboards, cellular phone numberpads, and handwriting recognition software. This result suggests that a listening keyboard would be an effective mode for alphanumeric input on future mobile devices.This study contributed to the development of SUITEKeys—a speech user interface for arbitrary keyboard and mouse access available for MS platforms as freeware.     

Impact of information systems on customers

The distinction between “users” of information systems of an organization and “customers” of the organization has not surfaced clearly in the literature on information systems planning and implementation. Also, the impact of the organization's information system on its customer is neither assessed nor clarified. This paper seeks to expose and, to some extent, fill these gaps. Based on his experience, the author derives three classes of assumptions likely to be made by organizations in managing the interface with their customers. Possible implications of such assumptions are discussed, and suggestions for planning the interface are offered.     

Affective command-based control system integrating brain signals in commands control systems

Speech interaction systems are currently highly demanded for quick hands-free interactions. Conventional speech interaction systems (SISs) are trained to the user’s voice whilst most modern systems learn from interaction experience overtime. However, because speech expresses a human computer natural interaction (HCNI) with the world, SIS design must lead to interface computer system that can receive spoken information and act appropriately upon that information. In spite of significant advancements in recent years SISs, there still remain a large number of problems which must be solved in order to successfully apply the SISs in practice and also comfortably accepted by the users. Among many other problems, problems of devising and efficient modeling are considered the primary and important step in the speech recognition deployment in hands-free applications. Meanwhile, the brain–computer interfaces (BCIs) allow users to control applications by brain activity. The work presented in this paper emphasizes an improved implementation of SIS by integrating BCI in order to associate the brain signals for a list of commands as identification criteria for each specific command for controlling the wheelchair with spoken commands.     

The efficacy of narrative video for raising awareness in ICT designers about older users’ requirements

This paper discusses the efficacy of narrative video to communicate some of the fundamental differences between older users of ICT interfaces and the interface designers who tend not to be familiar with the general perspectives and user requirements of this and other ‘non-typical’ target groups. Preliminary results show the impact such videos can have on relevant audiences’ perspective on designing systems for older adults. The findings suggest that they can influence the mind set of those with little or no experience of designing for older users and that this influence can persist in the longer term. The findings also suggest that the extent of this influence can be an appropriate alternative to that of meeting and interacting with older users in a user centred design process, which although very valuable can be a logistically (and otherwise) challenging element in the training of prospective software designers. The potential utility and limits of this approach are also discussed.     

QUEM: an achievement test for knowledge-based systems

This paper describes the Quality and Experience Metric (QUEM), a method for estimating the skill level of a knowledge based system based on the quality of the solutions it produces. It allows one to assess how many years of experience the system would be judged to have if it were a human by providing a quantitative measure of the system's overall competence. QUEM can be viewed as a type of achievement or job placement test administered to knowledge based systems to help system designers determine how the system should be used and by what level of user. To apply QUEM, a set of subjects, experienced judges, and problems must be identified. The subjects should have a broad range of experience levels. Subjects and the knowledge based system are asked to solve the problems; and judges are asked to rank order all solutions, from worst quality to best. The data from the subjects is used to construct a skill function relating experience to solution quality, and confidence bands showing the variability in performance. The system's quality ranking is then plugged into the skill function to produce an estimate of the system's experience level. QUEM can be used to gauge the experience level of an individual system, to compare two systems, or to compare a system to its intended users. This represents an important advance in providing quantitative measures of overall performance that can be applied to a broad range of systems     

Report on Dialogue Specification Tools

In this report we have presented some of the issues pertaining to the notations used in UIMSs. At the present time there are a small number of implemented UIMSs, so there is some experience to draw upon. This is the first workshop of this nature where there has been a significant number of participants with implementation experience. This experience seemed to raise more issues than it resolved. The conclusion that can be drawn from this is there is still a considerable amount of work to be done in notations for UIMSs.
One of the major problems encountered by this working group was the inability to compare different UIMSs. The systems discussed in this group have been used to produce user interfaces for different application areas, with different interaction styles and requirements. This makes it very difficult to compare the ease of use (for the user interface designer), and the quality of the resulting user interface. This problem would be partially solved by constructing a standard set of user interface problems. Each of the UIMSs could be used to solve these problems, and the results used as a means of comparison. This set of problems could be viewed as a benchmark test for user interface management systems. Along with developing the problems, techniques for measuring ease of use and the quality of the user interface must also be developed.     

Libra: a high fidelity knowledge-based system for recommending scheduling programs

Contemporary knowledge systems are usually neither easy to use or understand. We propose a new class of knowledge systems, which we call high fidelity systems, that use representations and processes that closely resemble the objects and tasks with which people are already familiar. To illustrate the concept of high fidelity, we describe Libra, one such system for recommending scheduling programs. Our initial experience with Libra and its usage suggests that high fidelity not only enhances the user acceptability of knowledge-based systems, but it also facilities high speed design and implementation.We chose to replicate the knowledge in Libra because it is already published, and because we wanted to show that a Libra user can have an interface similar to the diagrams drawn in the journal paper. The latter was used to describe the knowledge-based framework for selecting scheduling systems. If we can replicate them in the user interface, we would have successfully created a high fidelity system — that is, the Libra user interface would be at least as able to communicate the framework to the user as the journal paper.     

Expertech: Issues in the design and development of an intelligent help desk system

As more companies turn to expert systems to support traditional help desk activities, the need to understand the particular issues inherent in the development of such systems becomes increasingly important. This article describes the design and development of Expertech, a prototype expert system intended to assist a help desk operator in the resolution of common problems encountered by the users of a telecommunications network. Expertech, a rule-based system, is a partial implementation of a model of human expertise in network diagnosis. We argue that developers of intelligent help desk support systems (IHDSS) must consider several challenges not typically encountered in other environments. An IHDSS, for example, must consider the heterogeneous nature of the end users, and tailor its interface to encompass the varying technical knowledge of those users. Furthermore, an IHDSS must deal with the three-party nature of computer-based support, where the system does not interact directly with the end user. Instead, communication between the IHDSS and the end user takes place indirectly, through a human intermediary, the help desk operator. In the context of these considerations, we describe the approach we took in developing Expertech.     

Understanding the Relation Between Network Quality of Service and the Usability of Distributed Multimedia Documents

Network quality of service, as manifest in the delays users experience, effects both user perceptions and performance. Unfortunately, existing research on the usability of network-based documents and applications does not always adequately address the issue of network delays. In this article, we assert that researchers must document, and should consider manipulating, the delays users experience during studies exploring the usability of network-based computing systems. This article provides an overview of the factors that contribute to the delays users experience and the issues involved in modeling these delays. It also provides advice on how delays should be documented and discusses the advantages and disadvantages of the various techniques available for integrating delays into usability studies and controlled experiments. The existing literature reports numerous inconsistent results, which may be due to different experimental designs, participants, tasks, independent variables, and dependent variables. Therefore, this article concludes by outlining the experimental design considerations that must be considered as the relation between network quality of service and the usability of network-based computing systems is investigated. The result is a framework that will guide future research and allow more effective comparisons of the results of that research.