Thomas P. Moran

The Command Language Grammar: a representation for the user interface of interactive computer systems

This article introduces and discusses a specific grammatical structure—the Command Language Grammar (CLG)—as a representational framework for describing the user interface aspects of interactive computer systems. CLG partitions a system into a Conceptual Component (tasks and abstract concepts), a Communication Component (command language), and a Physical Component (display, keyboard, etc.), The components are further stratified into distinct Levels—a Task Level, a Semantic Level, a Syntactic Level, and an Interaction Level-each Level being a complete description of the system at its level of abstraction. Each Levels description contains procedures for accomplishing the tasks addressed by the system in terms of the actions available at that Level. That is, the system is described by progressive refinement. An extensive example, a small message-processing system, is described at all Levels in the CLG notation. CLG is discussed from three points of view: the Linguistic View sees CLG as elaborating the structure of the systems user interface and of the communication between the user and the system. The principal goal of CLG in this view is to lay out the space of command language systems. The Psychological View sees CLG as describing the users mental model of the system. The main concern in this view is with the psychological validity of the CLG description. The Design View sees CLG as a series of representations for specifying the design of a system. CLG proposes a top-down design process in which the conceptual model of the system is first specified and then a command language is created to communicate with it.

Notecards in a nutshell

NoteCards is an extensible environment designed to help people formulate, structure, compare, and manage ideas. NoteCards provides the user with a “semantic network” of electronic notecards interconnected by typed links. The system provides tools to organize, manage, and display the structure of the network, as well as a set of methods and protocols for creating programs to manipulate the information in the network. NoteCards is currently being used by more than 50 people engaged in idea processing tasks ranging from writing research papers through designing parts for photocopiers. In this paper we briefly describe NoteCards and the conceptualization of idea processing tasks that underlies its design. We then describe the NoteCards user community and several prototypical NoteCards applications. Finally, we discuss what we have learned about the systems strengths and weaknesses from our observations of the NoteCards user community.

Analogy considered harmful

The computer is like a typewriter. The computer is like a filing cabinet. The computer is a personal servant ready to obey your every command. It is often claimed (e.g., Carroll and Thomas [3], Rumelhart and Norman [7]) that the best way to introduce a new user to a computer system is to draw an analogy between the computer and some situation familiar to the user. Given the analogy, the new user can draw upon his knowledge about the familiar situation in order to reason about the workings of the mysterious new computer system. For example, if the new user wants to understand about how the computer file system works, he need only think about how an office filing cabinet works and then carry over this same way of thinking to the computer file system.

The evaluation of text editors: methodology and empirical results.

This paper presents a methodology for evaluating text editors on several dimensions: the time it takes experts to perform basic editing tasks, the time experts spend making and correcting errors, the rate at which novices learn to perform basic editing tasks, and the functionality of editors over more complex tasks. Time, errors, and learning are measured experimentally; functionality is measured analytically; time is also calculated analytically. The methodology has thus far been used to evaluate nine diverse text editors, producing an initial database of performance results. The database is used to tell us not only about the editors but also about the users—the magnitude of individual differences and the factors affecting novice learning.

“I'll get that off the audio”: a case study of salvaging multimedia meeting records

We describe a case study of a complex, ongoing, collaborative work process, where the central activity is a series of meetings reviewing a wide range of subtle technical topics. The problem is the accurate repxting of the results of these meetings, which is the responsibility of a single person, who is not well-versed in all the topics. We provided tools to capture the meeting discussions and tools to “salvage” the cap tured multimedia recordings. Salvaging is a new kind of activity involving replaying, extracting, organizing, and writing. We observed a year of mature salvaging work in the case study. From this we describe the nature of salvage work (the constituent activities, the use of the workspace, the affordances of the audio medium, how practices develop and differentiate, how the content material affects practice). We also demonstrate how this work relates to the larger work processes (the task demands of the setting, the interplay of salvage with capture, the influence on the people being reported on and reported to). Salvaging tools are shown to be valuable for dealing with free-flowing discussions of complex subject matter and for producing high quality documentation.

Pen-based interaction techniques for organizing material on an electronic whiteboard

This paper presents a scheme for extending an informal, penbased whiteboard system (the Tivoli application onthe Xerox LiveBoard) to provide interaction techniques that enable groups of users in informal meetings to easily organize and.rearrange material and to manage the space on the board. The techniques are based on the direct manipulation of boundaries and the implicit recognition of regions. The techniques include operations for shrinking and rearranging, structured borders that tessellate the board, freeform enclosures that can be split, fused, and linked, and collapsible annotations. Experience with using these techniques, the results of a user test, some design trade-offs and lessons, and future directions are discussed.

A confederation of tools for capturing and accessing collaborative activity

This paper presents a confederation of tools, called Coral, that combine to support the real-time capture of and subsequent access to informal collaborative activities. The tools provide the means to initiate digital multimedia recordings, a variety of methods to index those recordings, and ways to retrieve the indexed material in other settings. The current system emerged from a convergence of the WhereWereWe multimedia work, the Tivoli LiveBoard application, and the Inter-Language Unification distributed-object programming infrastructure. We are working with a specific user community and application domain, which has helped us shape a particular, demonstrably useful, configuration of tools and to get extensive real-world experience with them. This domain involves frequent discussion and decision-making meetings and later access of the captured records of those meetings to produce accurate documentation. Several aspects of Coral--the application tools, the architecture of the confederation, and the multimedia infrastructure--are described.

Design and technology for Collaborage: collaborative collages of information on physical walls

A Collaborage is a collaborative collage of physically represented information on a surface that is connected with electronic information, such as a physical In/Out board connected to a people-locator database. The physical surface (board) contains items that are tracked by camera and computer vision technology. Events on the board trigger electronic services. This paper motivates this concept, presents three different applications, describes the system architecture and component technologies, and discusses several design issues.

A perceptually-supported sketch editor

The human visual system makes a great deal more of images than the elemental marks on a surface. In the course of viewing, creating, or editing a picture, we actively construct a host of visual structures and relationships as components of sensible interpretations. This paper shows how some of these computational processes can be incorporated into perceptually-supported image editing tools, enabling machines to better engage users at the level of their own percepts. We focus on the domain of freehand sketch editors, such as an electronic whiteboard application for a pen-based computer. By using computer vision techniques to perform covert recognition of visual structure as it emerges during the course of a drawing/editing session, a perceptually supported image editor gives users access to visual objects as they are perceived by the human visual system. We present a flexible image interpretation architecture based on token grouping in a multiscale blackboard data structure. This organization supports multiple perceptual interpretations of line drawing data, domain-specific knowledge bases for interpretable visual structures, and gesture-based selection of visual objects. A system implementing these ideas, called PerSketch, begins to explore a new space of WYPIWYG (What You Perceive Is What You Get) image editing tools.

Getting into a system: External-internal task mapping analysis

A task analysis technique, called ETIT analysis, is introduced. It is based on the idea that tasks in the external world must be reformulated into the internal concepts of a computer system before the system can be used. The analysis is in the form of a mapping between sets of external tasks and internal tasks. An example analysis of several text editing systems is presented, and various properties of the systems are derived from the analysis. Further, it is shown how this analysis can be used to assess the potential transfer of knowledge from one system to another, i.e., how much knowing one system helps with learning another. Several issues are briefly discussed.