Integrating specification of human-computer interface with Jackson system development

Procedures for integrating task analysis and design of the human-computer interface (HCl) with a structured system development method, Jackson system development (JSD), are described. Process structure diagrams (PSDs), the major modelling notation of JSD, described tasks, and task specifications were evaluated for cognitive complexity. Task complexity analysis helped allocation and design of human tasks and to produce computer task support specifications. The cognitive dimension of task analysis highlighted the need for task support actions, especially information display support for working memory. Dialogue specification for a direct manipulation interface design was based on the JSD entity/event model from which the interaction metaphor, screen design, and permissible manipulations were derived. Further PSDs were constructed to specify interface object management processes. Preliminary evaluation of the method was carried out using JSD analysts. Results showed the method proved easy to learn even for non-HCl specialists.     

To model objects in information systems and user interfaces: implications for object-oriented methods

Abstract. A general way of contrasting the object-oriented to the function-oriented approach, called 'object-order' and 'function-order', is proposed in this paper. In addition, when modelling information systems, there is a third principle of ordering, 'subject-order'. Object and function-order are used to define the two approaches to modelling information systems and in human-computer interaction, in ways that are compatible to the corresponding distinction in programming. The conditions for selecting either of the two approaches are, however, not discussed here.
By means of an object-ordered method, e.g. Jackson System Development (JSD), an object-ordered model is produced, and the user interface that can be derived from the model is object-ordered too. However, other guidelines in JSD support subject-order. A function-ordered interface can be derived from the subject-ordered model. A computer system designed by means of an object-organized method may therefore obtain an interface that is partially object-ordered and partially function-ordered. Other object-oriented methods give guidelines for designing function-oriented interfaces without relating these guidelines to the model.
The system designer may benefit from having three principles of ordering when modelling a system. However, a user may be confused by an interface that sometimes gives preference to objects, sometimes to functions.     

Evaluation of user interfaces: EVADIS II— a comprehensive evaluation approach

As a result of the importance of the usability approach in system development and the EC's 'Directive concerning the minimum safety and health requirements for VDT workers' (EWG 1990), there is an accepted need for practical evaluation methods for user interfaces. The usability approach and the EC Directive are not restricted to user interface design, as they include the design of appropriate hardware and software, as well as organization, job, and task design. Therefore system designers are faced with many, often conflicting, requirements and need to address the question, 'How can usability requirements comprehensively be considered and evaluated in system development?' Customers buying hardware and software and introducing them into their organization ask, (How can I select easy-to-use hardware and software?' Both designers and customers need an evaluation procedure that covers all the organizational, user, hard- and software requirements. The evaluation method, EVADIS.II, we present in this paper overcomes characteristic deficiencies of previous evaluation methods. In particular, it takes the tasks, the user, and the organizational context into consideration during the evaluation process, and provides computer support for the use of the evaluation procedure.     

Formal models for user interface design artefacts

There are many different ways of building software applications and of tackling the problems of understanding the system to be built, designing that system and finally implementing the design. One approach is to use formal methods, which we can generalise as meaning we follow a process which uses some formal language to specify the behaviour of the intended system, techniques such as theorem proving or model-checking to ensure the specification is valid (i.e., meets the requirements and has been shown, perhaps by proof or other means of inspection, to have the properties the client requires of it) and a refinement process to transform the specification into an implementation. Conversely, the approach we take may be less structured and rely on informal techniques. The design stage may involve jotting down ideas on paper, brainstorming with users etc. We may use prototyping to transform these ideas into working software and get users to test the implementation to find problems. Formal methods have been shown to be beneficial in describing the functionality of systems, what we may call application logic, and underlying system behaviour. Informal techniques, however, have also been shown to be useful in the design of the user interface to systems. Given that both styles of development are beneficial to different parts of the system we would like to be able to use both approaches in one integrated software development process. Their differences, however, make this a challenging objective. In this paper we describe models and techniques which allow us to incorporate informal design artefacts into a formal software development process.     

Rapid Prototyping of Adaptable User Interfaces

User interface adaptation has been proposed in recent years as a means to achieve personalized accessibility and usability of user interfaces. Related user interface architectures, as well as a variety of related development method and tools, have also been elaborated. Admittedly, however, despite the recognized validity of the approach, which has been proved in practice in a series of prototype systems, the wider adoption and uptake of user interface adaptation approaches are still limited. One of the identified obstacles is the complexity intrinsic in designing such interfaces and the need of radically revising the current user interface design practice to account for (a) the alternative designs required for adaptation, (b) the parameters involved in driving adaptations (i.e., selecting among alternatives at a given point during interaction), and (c) the logic of adaptation at runtime. This article proposes a twofold tool-based support strategy for user interface adaptation development, based on (a) an adaptation development toolkit and related widget library, which directly embeds lexical level adaptations into common interactive widgets, and (b) embedding such a library in a common integrated development environment, thus allowing designers to define and view alternative adaptations at design time and create adaptable user interfaces through traditional prototyping. The aforementioned approach has been implemented in the domain of adaptable applications for older users, producing tools that are currently in use in the development of a large suite of interactive applications in various domains. The approach presented in this article is claimed to be the first and so far unique supporting rapid prototyping of adaptable user interfaces, thus minimizing the divergence between typical development practices and user interface adaptation development.     

A structured methodology for comparative evaluation of user interface designs using usability criteria and measures

Previous research in software ergonomics has indicated the importance of evaluating the usability of computer user interfaces. This paper presents a quantitative basis for selecting from among multiple alternative interfaces relative to multiple criteria of usability concern. The proposed model consists of two main phases: the prescreening phase and the evaluation phase. The prescreening phase involves expert judgment-based assessment with qualitative criteria. The first phase uses absolute measurement analytic hierarchy process (AHP) to filter possible alternative interfaces to a reasonable subset. The evaluation phase involves user-based assessment such as user testing, with quantitative criteria. The objective of the second phase is to evaluate a subset of alternatives using objective measures and to select the best alternative. A set of criteria and measures for evaluating the usability of computer software designs is presented. The proposed methodology is demonstrated in the interface design of a database system used to analyze trip cases information of nuclear power plant.Relevance to industry

There is currently a focus on the usability of interactive computer software. Software developers, interface designers or human factors engineers often confront the task of comparative evaluation among systems, versions or interface designs. The proposed methodology provides practitioners with a structured approach to select the best interface based on usability criteria and measures.     

Evaluation of user interfaces: EVADIS II— a comprehensive evaluation approach

Abstract

As a result of the importance of the usability approach in system development and the EC's ‘Directive concerning the minimum safety and health requirements for VDT workers’ (EWG 1990), there is an accepted need for practical evaluation methods for user interfaces. The usability approach and the EC Directive are not restricted to user interface design, as they include the design of appropriate hardware and software, as well as organization, job, and task design. Therefore system designers are faced with many, often conflicting, requirements and need to address the question, ‘How can usability requirements comprehensively be considered and evaluated in system development?’ Customers buying hardware and software and introducing them into their organization ask, (How can I select easy-to-use hardware and software?’ Both designers and customers need an evaluation procedure that covers all the organizational, user, hard- and software requirements. The evaluation method, EVADIS.II, we present in this paper overcomes characteristic deficiencies of previous evaluation methods. In particular, it takes the tasks, the user, and the organizational context into consideration during the evaluation process, and provides computer support for the use of the evaluation procedure.     

Reconciling usability and interactive system architecture using patterns

Traditional interactive system architectures such as MVC [Goldberg, A., 1984. Smaltalk-80: The Interactive Programming Environment, Addison-Wesley Publ.] and PAC [Coutaz, J., 1987. PAC, an implementation model for dialog design. In: Interact’87, Sttutgart, September 1987, pp. 431-436; Coutaz, J., 1990. Architecture models for interactive software: faillures and trends. In: Cockton, G. (Ed.), Engineering for Human-Computer Interaction, Elsevier Science Publ., pp. 137-153.] decompose the system into subsystems that are relatively independent, thereby allowing the design work to be partitioned between the user interfaces and underlying functionalities. Such architectures extend the independence assumption to usability, approaching the design of the user interface as a subsystem that can designed and tested independently from the underlying functionality. This Cartesian dichotomy can be fallacious, as functionalities buried in the application’s logic can sometimes affect the usability of the system. Our investigations model the relationships between internal software attributes and externally visible usability factors. We propose a pattern-based approach for dealing with these relationships. We conclude by discussing how these patterns can lead to a methodological framework for improving interactive system architectures, and how these patterns can support the integration of usability in the software design process.     

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.     

计算机文档的用户界面及其设计方法

计算机文档是软件系统的重要组成部分，它帮助用户与软件系统进行沟通，是软件用户界面的重要补充，本文针对目前计算机文档特别是用户文档不如人意的开发状况，强调用户文档对于软件可用性的重要性，提出用户文档生命周期的概念指导计算机文档开发，并对文档结构设计和文档用户界面设计进行了具体的设计。     

A method to elicit architecturally sensitive usability requirements: its integration into a software development process

In the Human-Computer Interaction (HCI) community, software usability has primarily been concerned with the presentation of information, more precisely with the user interface. However, some usability problems can prove costly to fix if the changes require modifications that reach beyond the presentation layer, namely those that cannot be easily accommodated by the software architecture. Taking into account some usability requirements earlier in the software development cycle, specifically prior to the architectural design phase, can reduce the cost of these modifications. There is a scarcity of methods and guidelines with the scope to direct users in eliciting the usability requirements that can impact the software architecture. This paper proposes a usability-driven adaptation of the quality attribute workshop (QAW) to assist software development organizations in discovering and documenting usability requirements. It shows how this method can be integrated into a software development process, by discussing how the existing software framework workflows can be adjusted to take this new activity into consideration. A preliminary exercise was conducted to help discern the utility and the limits of the proposed method. Participants with different levels of knowledge of usability and comprehension of the system being developed found the method constructive, as it guided them in identifying the architecturally relevant usability requirements. It also helped determine the usability aspects that would not necessarily have been defined if this technique had not been employed.     

The design of a fuzzy system shell using a database approach

This study presented a prototype of fuzzy system shell called FuzzyAccess. Using Microsoft Access database as a developing tools, the proposed system provided a friendly interface for user self-building a fuzzy system. A novice who has no programming-knowledge can also self-define a new fuzzy project. The main contributions of the proposed system were that using SQL method to search the candidate rules in rule evaluation stage and providing an integrated tuning interface for system adjustment. The SQL method can significantly reduce the search time in rule evaluation. The integrated tuning interface can assist user quickly inspecting the influence among different system parameters adjustment and reducing the system development time.     

Integrating methods of human-computer interface design with structured systems development

Various methods for specification and design of the human-computer interface have been proposed but practice of such methods is not widespread. Possible reasons for this may be the lack of integration of human-computer interface design with software engineering and the specialized nature of HCI methods. A method of interface design is proposed which integrates the development of the human-computer interface with structured systems analysis and design. The method covers task and user analysis, interface specification and dialogue design. A case study of a library system is used to illustrate the method which is discussed in relation to different approaches that have been adopted for interface specification and design. It is argued that software design methods should cover all aspects of process design and the human-computer interface.     

A framework for linking Soft Systems Methodology (SSM) and Jackson System Development (JSD)

Abstract. This paper describes a proposed framework for linking soft systems methodology (SSM), a problem structuring technique for use in messy, ill-defined problem situations, with Jackson System Development (JSD), an information system development methodology which has object-oriented characteristics. The approach taken has been to embed the modelling phase of JSD within SSM after the conceptual modelling stage, but before the debate on desirable and feasible change. The JSD modelling phase is carried out at a conceptual rather than a real world level. The framework comprises of a series of steps which enable JSD entity structure diagrams to be derived to a large extent from the activities in an SSM conceptual model. A data model may then be built up by exploding the activities in the conceptual model or by using 'conceptual hows' to identify more entities and actions. One of the main benefits expected to arise from the use of such a framework is an improved user requirement definition, which is important to successful systems implementation. The difficulties in actually achieving a link relate to the methodological and philosophical differences between SSM and JSD.     

User interface specification with sequence diagrams: an application to the AIRBUS A380 Datalink system

The development of user interfaces for safety critical systems is driven by requirements specifications. Because user interface specifications are typically embedded within complex systems requirements specifications, they can be intractable to manage. Proprietary requirements specification tools do not support the user interface designer in modelling and specifying the user interface. In this paper, a new way of working with embedded user interface specifications is proposed, exploiting sequence diagrams with a hypertext structure for representing and retrieving use cases. This new tool concept is assessed through an application to the requirements specification for the Airbus A380 air traffic control Datalink system; engineers involved in the development of the Airbus cockpit used a prototype of the tool concept to resolve a set of user interface design anomalies in the requirements specification. The results of the study are positive and indicate the user interface to requirements specification tools which user interface designers themselves need.     

水声传感器网络实验平台监控软件的开发

水下实验是水声传感器网络研究的重要手段,然而进行水下实验将需要大量的人力、物力和时间。水声传感器网络实验平台是提高水下通讯实验效率的有效解决方案。本文设计开发了水声传感器网络实验平台的监控软件,作为整个实验平台的系统管理层,为整个实验平台提供友好的用户接口,对水声传感器网络水下实验的测量、调试和分析提供可靠灵活的技术支持。     

Windows应用程序界面设计的若干问题

界面设计是软件开发的重要组成部分，本文论述了实现美观、实用的用户界面必须注意的几个问题，如界面设计的美学原则、可用性设计的概念、当用户或系统出错时的用户交互形式、帮助使用的用户辅助模式以及为使应用程序运行于不同计算机的显示类型设计。     

Web-Based Support for Cooperative Software Engineering

The Tatami project is building a system to support software engineering over the internet, exploiting recent advances in Web technology, interface design, and specification. Our effort to improve the usability of such systems has led us into algebraic semiotics, while our effort to develop better formal methods for distributed concurrent systems has led us into hidden algebra and fuzzy logic. This paper discusses the Tatami system design, especially its software architecture, and its user interface principles. New work in the latter area includes an extension of algebraic semiotics to dynamic multimedia interfaces, and integrating Gibsonian affordances with algebraic semiotics.     

Model-Driven Interactive System Design for Therapy Robots

Physiotherapy using intelligent robots is emerging as a new approach to recovery for many stroke patients. Although therapy robots have a strong potential in dealing with therapeutic and other medical applications, they have not been fully utilized in everyday therapy activities due to concerns over safety and the lack of friendly robot user/patient interaction models. From the viewpoint of software engineering, a user-centred design based on UML (Unified Modelling Language) has been known to be one of the best solutions to satisfy usability since the design process relies heavily on the analysis of users and their tasks to reach their goals. Therefore, a model-driven approach to interactive system design via UML for therapy robots is needed to make them usable in the real world. This paper proposes such approach and introduces a new graphical notation that describes user interface elements and the methods of connection with hardware/software objects. With the proposed abstract interaction models, prototyping interactive systems can be made faster and allows for their evaluation by users and system developers before implementation in order to improve usability from the perspectives of users and system developers.     

The influence of design decisions on the usability of direct manipulation user interfaces

It is assumed that the usability of direct manipulation user interfaces is influenced by a number of design aspects. In this experimental study, the order of command specification and the type of function activation were manipulated in a 2 × 2 factorial design, in order to test hypotheses H1, that object-function specification contributes more to usability than function-object specification; and H2. that the type of function activation (clicking vs. dragging) will influence the usability of direct manipulation user interfaces. Sixty-four subjects, balanced by sex, without computer experience, were assigned randomly to the four experimental conditions. The dependent variables include performance data such as time, efficiency and error rates (logfile-recording), and subjective user rating of the user interface (questionnaire). Whereas HI had to be rejected in this general form, a more elaborated analysis showed significant differences between the factor levels in terms of performance time and syntactically correct actions. Furthermore, the results of the study demonstrated evidence for H2.