John L. Sibert

George Washington University | GW · Department of Computer Science

Interactive systems are increasingly used in medical applications with the widespread availability of various imaging modalities. Gesture-based interfaces can be beneficial to interact with these kinds of systems in a variety of settings, as they can be easier to learn and can eliminate several shortcomings of traditional tactile systems, especiall...

Physicians are accustomed to using volumetric datasets for medical assessment, diagnosis and treatment. These modalities can be displayed with 3D computer visualizations for physicians to study the overall shape and internal anatomical structures. Gesturebased interfaces can be beneficial to interact with these kinds of visualizations in a variety...

In this paper, we describe a novel method to automatically generate synchronized dance motion that is perceptually matched to a given musical piece. The proposed method extracts 30 musical features from musical data as Well as 37 motion features from motion data. A matching process is then performed between the two feature spaces considering the co...

In this paper, we present a treatment of the issues that must be addressed in using vibrotactile cues for multiple purposes within a single simulation system. Similar to the problem of overloading the visual channel in typical graphical user interfaces, care must be taken to keep the added cognitive load devoted to the vibrotactile channel of the u...

This paper presents empirical results to support the use of vibrotactile cues as a means of improving user performance on a spatial task. In a building-clearing exercise, directional vibrotactile cues were employed to alert subjects to areas of the building that they had not yet cleared, but were currently exposed to. Compared with performing the t...

This paper presents a framework that helps in selecting the most appropriate timing for interruption as a way to mediate human interruptions by the computer. The conceptual framework is based on the new Interruption Taxonomy and uses Bayesian Belief Networks as a decision-support aid. A proof-of-concept model was constructed for the experimental se...

Recent trends in software development directed toward intelligence, distribution, and mobility have brought sophisticated software artifacts that often come with some unwanted side effects; frequent interruptions, for instance. In general, people are less effective when exposed to interruptions. We have created a framework that helps in selecting t...

Recent trends in software development directed toward intel- ligence, distribution, and mobility need to be followed by an increased sophistication in user interface design. Employment of theoretically sound methods for managing and coordinating complex information, and supporting graceful switching between tasks is especially critical for informat...

We present work on the development and deployment of a wearable system for displaying vibrotactile stimuli at multiple locations on a person. This system is targeted as a general-purpose controller, with the flexibility to support many types of output devices, such as pager motors, muffin fans, and solenoids. We describe the deployment of one confi...

This paper presents work we have done on the design and implementation of an untethered system to deliver haptic cues for use in immersive virtual environments through a body-worn garment. Our system can control a large number of body-worn vibration units, each with individually controllable vibration intensity. Several design iterations have helpe...

This paper presents results from work we have done into the combination of visual and vibrotactile cues for improving user interaction in virtual environments. Using a custom-designed control system, the intensity of a large number of low-cost vibrational devices can be independently controlled. Our current task is to determine the parameters and d...

This paper addresses the issue of improving the perception of contact that users make with purely virtual objects in virtual environments. Because these objects have no physical component, the user's perceptual understanding of the material properties of the object, and of the nature of the contact, is hindered, often limited solely to visual feedb...

Visual scanning is necessary for aviation safety and similar vigilance tasks, but little is known about its characteristics in such tasks, including possible changes with alertness and fatigue. We explored concurrent eye movements and human performance during a vigilance task designed to require frequent visual scanning. Effects of time and auditor...

This paper reports empirical results from two studies of effective user interaction in immersive virtual environments. The use of 2D interaction techniques in 3D environments has received increased attention recently. We introduce two new concepts to the previous techniques: the use of 3D widget representations; and the imposition of simulated surf...

The paper reports empirical results from two studies of effective user interaction in immersive virtual environments. The use of 2D interaction techniques in 3D environments has received increased attention recently. We introduce two new concepts to the previous techniques: the use of 3D widget representations; and the imposition of simulated surfa...

We have developed a system for remedial reading instruction that uses visually controlled auditory prompting to help the user with recognition and pronunciation of words. Our underlying hypothesis is that the relatively unobtrusive assistance rendered by such a system will be more effective than previous computer aided approaches. We present a desc...

We describe a shape-based visual interface for information retrieval and interactive exploration that exploits shape recognition. Our exploratory system uses procedurally generated shapes coupled with an underlying text-retrieval engine. A visual interface based on 3D shapes (glyphs) enhances traditional text-based queries and summarization. Our in...

This paper reports empirical results from a study into the use of 2D widgets in 3D immersive virtual environments. Several researchers have proposed the use of 2D interaction techniques in 3D environments, however little empirical work has been done to test the usability of such approaches. We present the results of two experiments conducted on low...

The study of human-computer interaction within immersive virtual environments requires us to balance what we have learned from the design and use of desktop interfaces with novel approaches to allow us to work effectively in three dimensions. While some researchers have called for revolutionary interfaces for these new environments, devoid of two-d...

The study of human-computer interaction within immersive virtual environments requires us to balance what we have learned from the design and use of desktop interfaces with novel approaches to allow us to work effectively in three dimensions. While some researchers have called for revolutionary interfaces for these new environments, devoid of two-d...

We have conducted three related experiments in order to analyze the performance of the index finger as a pointing device. The results indicate that the performance of the index finger is significantly better as a direct pointing device [1] than as an indirect pointing device using an isometric finger-controlled joystick (Trackpoint). We included a...

Information visualization focuses on the use of visual means for exploring non-visual information. While free-form text is a rich, common source of information, visualization of text is a challenging problem since text is inherently non-spatial. The paper explores the use of implicit surface models for visualizing text. The authors describe several...

This preliminary study explores the use of Heart Rate Variability (HRV) as an indicator of user state. In the study, a visual display is used to vary the levels of a complexity factor to assess the impact on user mental effort in a monitoring task Mental effort is measured both subjectively and physiologically. Two findings indicate the potential v...

At Wellesley College, very rarely do the Fine Art and Computer Science faculty cross paths. At least that was the case until last year when we taught an experimental course that brought together the work we were doing in our respective corners of ...

Because of its ability to provide platform independent programs and active content on web pages, Java has created much excitement in the computer science community. However, much of the computer science community does not have a good understanding of the Java technology. Java is much more than simply a language for developing programs which run on...

The index (first) finger of the dominant hand seems to be an intuitively natural and efficient means for pointing tasks. This paper presents the design of a device to enable pointing with the index finger as an interaction technique in mobile computers. The device, which uses infrared emission and detection to determine where on a screen the finger...

A software architecture is presented that uses structural properties of human dialogues to express human-computer dialogues. It allows control requests from the user to negotiate the flow of control of the dialogue, without being restricted to a stack-based control architecture. The architecture uses a notation with syntactical parts that separate...

Interruptions and cancellations are important parts of a user interface, yet they are treated as special cases in user interface design and notations. In an effort to build a dialogue notation that allows for effective definition of these commands or user turns, we present a behavioral definition of interruptions and cancellations. We show several...

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 o...

People have severe problems wayfinding in large virtual worlds. However, current implementations of virtual worlds provide little support for effective wayfinding. We assert that knowledge about human wayfinding in the physical world can be applied to construct aids for wayfinding in virtual worlds. An experiment was conducted to determine whether...

As important as navigation is to human performance in virtual worlds, it is an often overlooked problem in the design process. This article reports an experiment intended to show that real‐world wayfinding and environmental design principles are effective in designing virtual worlds that support skilled wayfinding behavior. The study measures parti...

Maintaining knowledge of current position and orienta- tion is frequently a problem for people in virtual environ- ments. In this paper we present a toolset of techniques based on principles of navigation derived from real world analogs. We include a discussion of human and avian navigation behaviors and show how knowledge about them were used to d...

Focus in natural language processing is used to keep track of the attentional space of the participants in the dialogue. Graphical interfaces have still to benefit from the use of this level of communication. We discuss a graphical interface counter part called a focus space. Focus spaces can be used to combine multiple interaction styles (e.g. nat...

Human-computer interaction (HCI) research is concerned with the design of interfaces that allow easy and efficient use of computer systems. This report is the result of a workshop held to define the state of the art and to identify HCI research directions. The workshop was held on March 4 and 5, 1991 at George Washington University. The participant...

The ConMod system is a modelling tool for the construction, verification, and communication of user conceptual models. A basic premise behind the research is that consistency at the syntactic and lexical levels cannot counteract conceptual inconsistencies designed into a system, and a working definition of conceptual consistency is maintained in a...

This work recognizes the importance of relationships between objects in the design of object-oriented systems. Such relationships exist that represent constraints between objects to be maintained at run-time. Maintaining these constraints requires that objects react in a coordinated fashion to incoming messages. We propose an object-oriented model...

The construction and maintenance of interactive user interfaces have been simplified by the development of a generation of software tools. The tools range from window managers, toolkits, and widget sets to user interface management systems and knowledge-based design assistants. However, only a small number of the tools attempt to incorporate princi...

One area of PACS research at the Georgetown University Medical Center, Department of Radiology, relates to the user interface of the PACS workstations. Other research areas include network simulation, data compression, digital radiology, image processing, and teaching workstation development. The major focus of this paper is a presentation of a PAC...

A PACS must provide a user interface which is acceptable to all potential users of the system. Observations and interviews have been conducted with six radiology services at the Georgetown University Medical Center, Department of Radiology, in order to evaluate user interface requirements for a PACS system. Based on these observations, a conceptual...

The authors describe how to model the interface between the user interface and the application. Their conceptual modeling system contains constructs and abstraction mechanisms that structure knowledge in a model. They use the interaction semantics of a spreadsheet to illustrate the practical applications of their system.< >

Background: Traditional paint programs can be criticized on the grounds that they provide fewer degrees of freedom than conventional artistic media. Mouse or tablet input devices usually provide only (x, y) spatial information. Thus most paint programs allow continuous control of the path of a stroke, but render it with a single “brush shape” of fi...

This is a report of a workshop task force on tools and methodology for user interface development. The objective of the task force was to characterize in a broad way the understanding of procedures for enduser interface design and development. Discussion often focused on tools to assist designers and implementers, paying particular attention to res...

Recently there has been increasing attention to character recognition/graphical user interfaces under the name of “gesture input”. This technique actually has a long history: “sketch recognition” interfaces of 15 or more years ago were highly praised [Applicon 73], and user interfaces using handwriting input before the wide use of text keyboards we...

The George Washington User Interface Management System (GWUIMS) has been designed as a test bed for comparing user interface models, as a tool for rapidly prototyping highly interactive graphic user interfaces, and as a vehicle for investigating the applicability of knowledge-based technology to user interface design. The GWUIMS was designed and im...

The subject of User Interface Management Systems (UIMS) has been a topic of research and debate for the last several years. The goal of such systems has been to automate the production of user interface software. The problem of building quality user interfaces within available resources is a very important one as the demand for new interactive prog...

Recently there has been increasing attention to character recognition/graphical user interfaces under the name of “gesture input”. This technique actually has a long history: “sketch recognition” interfaces of 15 or more years ago were highly praised [Applicon 73], and user interfaces using handwriting input before the wide use of text keyboards we...

This paper summarizes the keynote presentation in the topical area of the relationship between user interface management systems (UIMS) and application software. K2 were asked to prepare this presentation because of our implementation experiences in a UIMS environment. Accordingly we will focus on our experiences during our implementation effort. B...

The design of the user interface management system (UIMS) is discussed within the context of the problems that it is intended to solve. The aim is not to review the various forms and strategies that have been proposed and used for UIMS development but rather to clarify the environment of a UIMS. The issues, which relate the services of a UIMS to th...

The purpose of this case study was to document and evaluate the application of a top-down design methodology (Foley & van Dam, 1982) to a pre-existing computer system to test the methodology's usefulness as well as to gain insights into the design process itself. System experts advocate design of a system “top-down” instead of “bottom-up” as a way...

User computer interaction as a conversation is discussed. The design of user interfaces which depends on viewing communications between a user and the computer as a conversion is presented. This conversation includes inputs to the computer (outputs from the user), outputs from the computer (inputs to the user), and the sequencing in both time and s...

In this paper we present a conceptual model of raster graphics systems which integrates, at a suitable level of abstraction, the major features found in both contemporary and anticipated graphics systems. These features are the refresh buffer; the image creation (scan-conversion) system; the single address-space architecture which integrates the ad...

The use of color in thematic mapping is considered within the framework of a transformational view of the map-making process. Three examples using color are presented to show how increasingly complex models are displayed. It is suggested that by adopting this view of the use of color, a foundation for investigating the further transformation from m...

This paper describes a method of enhancing feedback for Urban Search and Rescue (USAR) robot operators through the use of a wearable vibrotactile display. The display provides vibrotactile feedback corresponding to sensor data collected by the robot. A USAR robot may be equipped with a variety of sensors including proximity, temperature, motion, an...

A data-base query system has been developed at the Los Alamos Scientific Laboratory for use by the Conservation Division of the United States Geologial Survey as a tool for regulatory decision making. The data base has a network structure based on the CODASYL standard. Important aspects of the data-base retrieval system are its use of a query langu...

Typescript (photocopy). Thesis (M.A.)--Miami University, Dept. of Geography, 1971. Includes bibliographical references.