5342280
Intelligent gaze-added interfaces
We discuss a novel type of interface, the intelligent gaze-added interface, and describe the design and evaluation of a sample gaze-added operating-system interface. Gaze-added interfaces, like current gaze-based systems, allow users to execute commands using their eyes. However, while most gaze-based systems replace the functionality of other inputs with that of gaze, gaze-added interfaces simply add gaze functionality that the user can employ if and when desired. Intelligent gaze-added interfaces utilize a probabilistic algorithm and user model to interpret gaze focus and alleviate typical problems with eye-taking data. We extended a standard WIMP operating-system interface into a new interface, IGO, that incorporates intelligent gaze-added input. In a user study, we found that users quickly adapted to the new interface and utilized gaze effectively both alone and with other inputs.
12617679
Human Symbol Manipulation Within an Integrated Cognitive Architecture
This article describes the Adaptive Control of Thought-Rational (ACT-R) cognitive architecture (Anderson et al., 2004; Anderson & Lebiere, 1998) and its detailed application to the learning of algebraic symbol manipulation. The theory is applied to modeling the data from a study by Qin, Anderson, Silk, Stenger, & Carter (2004) in which children learn to solve linear equations and perfect their skills over a 6-day period. Functional MRI data show that: (a) a motor region tracks the output of equation solutions, (b) a prefrontal region tracks the retrieval of declarative information, (c) a parietal region tracks the transformation of mental representations of the equation, (d) an anterior cingulate region tracks the setting of goal information to control the information flow, and (e) a caudate region tracks the firing of productions in the ACT-R model. The article concludes with an architectural comparison of the competence children display in this task and the competence that monkeys have shown in tasks that require manipulations of sequences of elements.
29133778
Toward a real-time model-based training system
This article describes the development of a real-time model-based training system that provides adaptive ''over-the-shoulder'' (OTS) instructions to trainees as they learn to perform an Anti-Air Warfare Coordinator (AAWC) task. The long-term goal is to develop a system that will provide real-time instructional materials based on learners' actions, so that eventually the initial set of instructions on a task can be strengthened, complemented, or overridden at different stages of training. The training system is based on the ACT-R architecture, which serves as the theoretical background for the cognitive model that monitors the learning process of the trainee. An experiment was designed to study the impact of OTS instructions on learning. Results showed that while OTS instructions facilitated short-term learning, (a) they took time away from the processing of current information, (b) their effects tended to decay rapidly in initial stages of training, and (c) their effects on training diminished when the OTS instructions were proceduralized in later stages of training. A cognitive model that learned from both the upfront and OTS instructions was created and provided good fits to the learning and performance data collected from human participants. Our results suggest that to fully capture the symbiotic performance between humans and intelligent training systems, it is important to closely monitor the learning process of the trainee so that instructional interventions can be delivered effectively at different stages of training. We proposed that such a flexible system can be developed based on an adaptive cognitive model that provides real-time predictions on learning and performance.
1998598
Dynamic Student Modelling in an Intelligent Tutor for LISP Programming
We describe an intelligent tutor for LISP programming. This tutor achieves a set of pedagogical objectives derived from Anderson's (1983) learning theory provide instruction in the context of problem-solving, have the student generate as much of each solution as possible, provide immediate feedback on errors, and represent the goal structure of the problem-solving. The tutorial interface facilitates communication and prevents distracting low-level errors Field tests of the tutor in college classes demonstrate that it is more effective than conventional classroom instruction.
195901903
Integrating analogical mapping and general problem solving: the path-mapping theory
This article describes the path-mapping theory of how humans integrate analogical mapping and general problem solving. The theory posits that humans represent analogs with declarative roles, map analogs by lower-level retrieval of analogous role paths, and coordinate mappings with higher-level organizational knowledge. Implemented in the ACT-R cognitive architecture, the path-mapping theory enables models of analogical mapping behavior to incorporate and interface with other problem-solving knowledge. Path-mapping models thus can include task-specific skills such as encoding analogs or generating responses, and can make behavioral predictions at the level of real-world metrics such as latency or correctness. We show that the path-mapping theory can successfully account for the major phenomena addressed by previous theories of analogy. We also describe a path-mapping model that can account for subjects' incremental eye-movement and typing behavior in a story-mapping task. We discuss extensions and implications of this work to other areas of analogy and problem-solving research.
17702751
The Geometry Tutor
The tutor for doing proofs in high school geometry consists of a cot of ideal and buggy rules (IRR), a tutor, and an interface. The IBR is responsible for ehiuertly computing matcher, to all the correct and incorrect rules The interface is responsible for interacting with the student and graphically representing the proof. The tutor is responsible for directing the IBR and interface to achieve a current tutorial strategy. The strategy wo employ involves tracing the student's behavior in terms of what rules in the IBR it instantiates, correcting the student when behavior deviates below a minimum threshold, and helping the student over hurdles. While incomplete, current evidence indicates the geometry tutor is guite effective. 
 
The Advanced Computer Tutoring Project has been working on the development of intelligent computerhased tutors for mathematics and science subjects in the range of senior high-school to junior college. This paper describes the general framework that we have developed and its instantiation in the case of a tutor tor generating proofs in geometry. First, we will describe the general philosophy of out tutoring efforts. Second, we will describe the basic structure of the geometry tutor that we have built. Third, we will describe the ongoing efforts to evaluate the tutor.
45489934
Usability Assessment of Collaborative Shared-Space Telepresence Shopping Services
This paper describes the methodology and procedure of usability trials undertaken as part of the ACTS Teleshoppe project; it also details and analyses the results of the trials. The aim of the trials was to assess user attitudes to a collaborative shared-space shopping service. Usability data were obtained using a series of Likert-style questionnaires and through a 'focus group' discussion performed with a representative subset of the trial participants. The paper presents this data and draws conclusions relevant to the future direction of research and implementation for such shopping services. In particular, the results of the trials indicate a generally positive attitude towards the collaborative shopping service used. Furthermore, those aspects of the service viewed negatively by the users are for the most part aspects which can be easily rectified and not due to technological limitations.
5060275
A CAD-based computer vision system
A vision system for recognizing rigid and articulated three-dimensional objects in two-dimensional images is described. Geometrical models are extracted from a commercial computer aided design package. The models are then augmented with appearance and functional information which improves the system's hypothesis generation, hypothesis verification, and pose refinement. Significant advantages over existing CAD-based vision systems, which utilize only information available in the CAD system, are realized. Examples show the system recognizing, locating, and tracking a variety of objects in a robot work-cell and in natural scenes.
2301308
Recovering from Distributable Thread Failures with Assured Timeliness in Real-Time Distributed Systems
We consider the problem of recovering from failures of distributable threads with assured timeliness. When a node hosting a portion of a distributable thread fails, it causes orphans - i.e., thread segments that are disconnected from the thread's root. We consider a termination model for recovering from such failures, where the orphans must be detected and aborted, and failure-exception notification must be delivered to the farthest, contiguous surviving thread segment for resuming thread execution. We present a realtime scheduling algorithm called AUA, and a distributable thread integrity protocol called TP-TR. We show that AUA and TP-TR bound the orphan cleanup and recovery time, thereby bounding thread starvation durations, and maximize the total thread accrued timeliness utility. We implement AUA and TP-TR in a real-time middleware that supports distributable threads. Our experimental studies with the implementation validate the algorithm/protocol's time-bounded recovery property and confirm their effectiveness
32806401
Use of multiple difference-of-Gaussian filters to verify geometric models
Abstract Experiments are reported with a program which recognizes London buses in busy street scenes. The program uses a 3D model of a bus. together with knowledge of camera and scene parameters, to compute the visual appearance of possible target events. In earlier work this took the form of 2D templates, which identify locations within the image where abrupt discontinuities of grey-value are expected. Each template corresponds to an hypothesis which is verified by measuring the agreement between the predicted features and the response of a Sobel filter to the image data. This paper reports an extension to the program which offers improved selectivity, and a more general-purpose method of linking predicted features to detected imageattributes. Multiple difference-of-Gaussian filters perform an initial object-independent analysis of the image to provide an intermediate domain in which object-dependent features, predicted by hypothesized instances of the model, are tested.
14337981
The nature of indexing: how humans and machines analyze messages and texts for retrieval - Part II: Machine indexing, and the allocation of human versus machine effort
Abstract Does human intellectual indexing have a continuing role to play in the face of increasingly sophisticated automatic indexing techniques? In this two-part essay, a computer scientist and long-time TREC participant (Perez-Carballo) and a practitioner and teacher of human cataloging and indexing (Anderson) pursue this question by reviewing the opinions and research of leading experts on both sides of this divide. We conclude that human analysis should be used on a much more selective basis, and we offer suggestions on how these two types indexing might be allocated to best advantage. Part I of the essay critiques the comparative research, then explores the nature of human analysis of messages or texts and efforts to formulate rules to make human practice more rigorous and predictable. We find that research comparing human versus automatic approaches has done little to change strongly held beliefs, in large part because many associated variables have not been isolated or controlled. Part II focuses on current methods in automatic indexing, its gradual adoption by major indexing and abstracting services, and ways for allocating human and machine approaches. Overall, we conclude that both approaches to indexing have been found to be effective by researchers and searchers, each with particular advantages and disadvantages. However, automatic indexing has the over-arching advantage of decreasing cost, as human indexing becomes ever more expensive.