In current interfaces, users select objects, apply operations, and change viewing parameters in distinct steps that require switching attention among several screen areas. Our See-Through Interface ™ software reduces steps by locating tools on a transparent sheet that can be moved over applications with one hand using a trackball, while the other hand controls a mouse cursor. The user clicks through a tool onto application objects, simultaneously selecting an operation and an operand. Tools may include graphical filters that display a customized view of application objects. Compared to traditional interactors, these tools save steps, require no permanent screen space, reduce temporal modes, apply to multiple applications, and facilitate customization. This paper presents a taxonomy of see-through tools that considers variations in each of the steps they perform. As examples, we describe particular see-through tools that perform graphical editing and text editing operations.

this paper, we propose a general framework for implementing undo in collaborative systems. The framework allows users to individually reverse their own changes, taking into account the possibility of conflicts between different users' operations that may prevent an undo. The proposed framework has been incorporated into DistEdit, a toolkit for building group text-editors. Based on our experience with DistEdit's undo facilities, we discuss several issues that need to be taken into account in using the framework, in order to ensure that a reasonable undo behavior is provided to users. We show that the framework is also applicable to single-user systems, since the operations to undo can be selected not just on the basis of who performed them, but by any appropriate criterion, such as the document region in which the operations occurred or the time interval in which the operations were carried out. Categories and Subject Descriptors: D.2.2 [Software Engineering]: Tools and Techniques -- User Interfaces; H.1.2 [Models and Principles]: User/Machine Systems -- Human Factors; H.2.2 [Database

Formal and semiformal specification techniques have been applied to many aspects of software development. Their value is that they permit a designer to describe precisely the external

Most programming in the Garnet system uses a Over the last three years of using the Garnet system to declarative style that eliminates the need to write new create dozens of large-scale user interfaces, we have methods. One implication is that the interface to ob-

This report gives a survey of user interface languages and formal representations of user interfaces. The following aspects of User Interface Languages are considered: ffl expressiveness ffl readability ffl evaluation (is it possible to evaluate the ergonomic and functional quality of the user interface from the representation) ffl manipulation ffl compilation/interpretation ffl possibility to include knowledge representation.

Feedback plays an important role in human-computer interaction. It provides the user with evidence of closure, thus satisfying the communication expectations that users have when engaging in a dialogue. In this paper we present a model identifying five feedback states that must be communicated to the user to fulfill the communication expectations of a dialogue. The model is based on a linguistics theory of conversation, but is applied to a graphical user interface. An experiment is described in which we test users' expectations and their behavior when those expectations are not met. The model subsumes some of the temporal requirements for feedback previously reported in the human-computer interaction literature. Keywords Human-computer dialogues, feedback, conversational dialogues, states of understanding, collaborative view of conversations. INTRODUCTION Adequate feedback is a necessary component of both human-human and human-computer interaction. In human conversations, we use l...

Feature interaction problems are currently a major roadblock to extending and changing telephone switching systems, which have to follow market needs quickly. Such problems appear already in the requirements specifications. We avoid certain kinds of feature interactions by employing a more modular specification structure. First, we show how the details of the users' interface, like buttons and ring tones, can be encapsulated and separated from the system's functionality. Such an architecture could be realized even within the structure of the current standard for the Intelligent Network (IN). Second, we argue that the requirements for the Plain Old Telephone Service (POTS) comprehend several different concerns, and that separate requirement concerns should be separated in the specification. We employ the Functional Documentation approach [PaMa95, vSPM93, vS92a] and investigate how it can be extended to group requirement concerns, and to cover not only one but a sequence of development contracts. Our approach is related to the standard refinement approach for software development. But when we refine a specification to introduce new services, we order the refinement steps (i.e., the new required properties) by the likeliness by which they must be taken back, and we document the dependences between these steps explicitly. In the appendix, we provide a case study that applies our ideas.

The ability to undo operations is a standard feature in most single-user interactive applications. However, most current collaborative applications that allow several users to work simultaneously on a shared document lack undo capabilities; those which provide undo generally provide only a global undo, in which the last change made by anyone to a document is undone, rather than allowing users to individually reverse their own changes. In this paper, we propose a general framework for undoing actions in collaborative systems. The framework takes into account the possibility of conflicts between different users' actions that may prevent a normal undo. The framework also allows selection of actions to undo based on who performed them, where they occurred, or any other appropriate criterion. The proposed framework have been incorporated in DistEdit, a toolkit for building text group editors. Based on our experience, we discuss methods for maintaining the undo information in a groupware env...

An undo facility is an essential component of most interactive applications. In current operating system shells, whether textual or graphical, such facilities are typically very poor. Algorithms are presented for adding a recovery mechanism to a shell which allows previous commands to be selectively undone and redone, and previous versions of files to be recovered. The recovery mechanism involves making the shell control resources in a more intelligent way. Programs are run under greater control, with the shell monitoring and analysing their resource requests. This provides better high level information to the shell and, for example, provides techniques to prevent foreign or untrustworthy programs from doing any damage, and to reduce problems with conflicting resource requests from concurrent programs. A prototype implementation has been implemented to investigate the convenience and natural feel of these facilities. 1 Introduction A recovery ability is a crucial feature that many int...

we accept this thesis as conforming