While software architecture has become an increasingly important research topic in recent years, insufficient atten-tion has been paid to methods for evaluation of these archi-tectures. Evaluating architectures is dijjicultfor two main reasons. First, there is no common language used 10 de-scribe different architectures. Second, there is no clear way of understanding an architecture with respect to an organi-zation’s ll~e cycle concerns—software quality concerns such as maintainability, portability, modularity, reusability, and so forth. This paper addresses these shortcomings by describing three perspectives by which we can understand the description of a soflware architecture and then propos-ing ajve-step method for analyzing software architectures called SAAM (Software Architecture Analysis Method). We illustrate the method by analyzing three separate user in-terface architectures with respect to the qualiiy of modifi-ability. 1

problematic and forces the human VE participant to attend to the interface and its control knobs in addition to or instead of the goals and constraints of the task at hand. If the intention of the human VE participant is, e.g., to observe some object X, then allowing him or her to simply tell the system, Show me object X is a more direct and productive interface. This is an instance of task level interaction. In earlier work we characterized the levels of abstraction at which one can interact with virtual objects and processes, and we described the varying access panels one obtains (5). Here we will describe a system for specifying behaviors for virtual cameras in terms of task level goals and constraints. As in our earlier work on camera control (6, 7), we make task level control available as well as enabling various direct manipulation metaphors. This paper describes a framework for exploring intelligent camera controls in a 3D virtual environment. It presents a methodology for ...

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ing combines and transforms events coming from the presentation techniques into higher level events for higher abstractions. Conversely, concretizing decomposes and transforms high level information into low level information. The lowest level of the dialogue controller is in contact with the presentation techniques provided by the toolkit. This boundary is a rather fuzzy frontier. In general, user interface toolkits such as the X Intrinsics, provide an abstraction mechanism for defining new interaction techniques. However, it is not always possible to build new interaction techniques from the predefined building blocks of the toolkit. For example, in an earlier version of the X intrinsics, interaction techniques would occupy rectangular areas only. In such conditions, the notion of a wall in a floor plan drawing editor, could not be implemented as a diagonal line widget. Instead, a presentation object "wall" would be defined as a new abstraction in the dialogue controller portion. Thi...

This paper presents one French research effort in the domain of multimodal interactive systems: the Pole Interface Homme-Machine Multimodale. It aims at clarifying the distinction between multimodal and multimedia systems and suggests a classification illustrated with current interactive systems. 1. Introduction Graphical user interfaces (GUI) are now common practice. Although not fully satisfactory, concepts in GUI are well understood and software tools such as interaction toolkits and UIMS technology, are widely available. Parallel to the development of graphical user interfaces, natural language processing, computer vision, and gesture analysis [12] have made significant progress. Artificial and virtual realities are good examples of systems based on the usage of multiple modalities and medias of communication. As noted by Krueger in his latest book "Artificial Reality II", multimodality and multimedia open a complete new world of experience [13]. Clearly, the potential for this ...

... advent of new technologies and user-centred concerns, the user interface portion of interactive systems is becoming increasingly large and complex. In this article, we discuss agent-based architectural styles and show how sound tradeoffs between conflicting requirements and properties can be done using the PAC-Amodeus conceptual model.

George Santayana's statement, "Those who cannot remember the past are condemned to repeat it, " is only half true. The past also includes successful histories. If you haven't been made aware of them, you're often condemned not to repeat their successes. In a rapidly expanding field such as software engineering, this happens a lot. Extensive studies of many software projects such as the Standish Reports offer convincing evidence that many projects fail to repeat past successes. This paper tries to identify at least some of the major past software experiences that were well worth repeating, and some that were not. It also tries to identify underlying phenomena influencing the evolution of software engineering practices that have at least helped the author appreciate how our field has gotten to where it has been and where it is. A counterpart Santayana-like statement about the past and future might say, "In an era of rapid change, those who repeat the past are condemned to a bleak future. " (Think about the dinosaurs, and think carefully about software engineering maturity models that emphasize repeatability.) This paper also tries to identify some of the major sources of change that will affect software engineering practices in the next couple of decades, and identifies some strategies for assessing and adapting to these sources of change. It also makes some first steps towards distinguishing relatively timeless software engineering principles that are risky not to repeat, and conditions of change under which aging practices will become increasingly risky to repeat.

Building a software environment for Computer Algebra is quite a complex issue. Such an environment may include one or more Symbolic Computation tools, some devices, such as plotting engines or code generators, and a way to link others scientific applications. It is also expected that any of these components may be run on a remote processor and that the whole system is used via a convenient graphical user interface. The natural extensibility of Computer Algebra software, as well as the diversity of the needs expressed by their users, necessitate a highly open and customizable software architecture allowing different kinds of extensions and adaptations. Our approach consists of building the environment by composition of separately developed packages, using state of the art software engineering technologies in the spirit of the tool integration paradigm. This way, the different software components should be able to exchange data and freely cooperate with each other, without being too tigh...

In this paper we review the current state of the problem solving environment (PSE) field and make projections for the future. First we describe the computing context, the definition of a PSE and the goals of a PSE. The state-of-the-art is summarized along with sources (books, bibliographics, web sites) of more detailed information. The principal components and paradigms for building PSEs are presented. The discussion of the future is given in three parts: future trends, scenarios for 2010/2025, and research

. It is now widely recognized that powerful architecture elements are needed for implementing highly-interactive business-oriented applications during at least two stages of the whole lifecycle, namely the specification and the design. In this paper, we deal with the architecture model of the TRIDENT project, which introduces three components : the semantic core component, the dialog component and the presentation component. This is a hierarchical object -oriented architecture relying on the use of three kinds of objects : application objects, dialog objects, and interaction objects. Specification and rule languages are given for developing the dialog component. An abstract data model is used for characterizing the application objects. Selection rules are given for choosing appropriate interaction objects for the presentation component according to the abstract data model and to the user level. 1 Introduction It is highly desirable to have a stable methodology addressing the whole dev...