23810734
Requirements Development in Scenario-Based Design
We describe and analyze the process of requirements development in scenario based design through consideration of a case study. In our project, a group of teachers and system developers initially set out to create a virtual physics laboratory. Our design work centered on the collaborative development of a series of scenarios describing current and future classroom activities. We observed classroom scenarios to assess needs and opportunities, and envisioned future scenarios to specify and analyze possible design moves. We employed claims analysis to evaluate design trade-offs implicit in these scenarios, to codify the specific advantages and disadvantages in achieving requirements. Through the course of this process, the nature of our project requirements has evolved, providing more information but also more kinds of information. We discuss the utility of managing requirements development through an evolving set of scenarios, and the generality of the scenario stages from this case study.
9978523
Community collective efficacy: structure and consequences of perceived capacities in the Blacksburg Electronic Village
Bandura's social cognitive construct "perceived self-efficacy" has been used widely to understand individual behavior as a function of domain-specific beliefs about personal capacities. Collective efficacy is the extension of the self-efficacy construct to organizations and groups; it refers to beliefs about collective capacities in specific domains. Our research is investigating the use of collective efficacy in understanding attitudes and behaviors of members of proximal residential communities with respect to issues like attachment, engagement, and sociality, specifically as modulated by use of the Internet and community networks. This paper describes our analysis of the structure and external validity of the collective efficacy construct.
15595014
Notification and awareness: synchronizing task-oriented collaborative activity
People working collaboratively must establish and maintain awareness of one another's intentions, actions and results. Notification systems typically support awareness of the presence, tasks and actions of collaborators, but they do not adequately support awareness of persistent and complex activities. We analysed awareness breakdowns in use of our Virtual School system--stemming from problems related to the collaborative situation, group, task and tool support--to motivate the concept of activity awareness. Activity awareness builds on prior conceptions of social and action awareness, but emphasizes the importance of activity context factors like planning and coordination. This work suggests design strategies for notification systems to better support collaborative activity.
148806746
Human-computer interaction: psychology as a science of design.
7723669
Better home shopping or new democracy?: evaluating community network outcomes
This is a perspective paper on community networks - socio-technical infrastructures supporting villages, towns, and neighborhoods. Community networking is well-established, world wide, and addresses critical societal issues, such as the “crisis of community” and the sociality of the Internet. However, community network projects have not emphasized evaluation. Relatively little is known about the economic, social, and psychological consequences of community networks for the individuals, groups, and communities served. Evaluating community networks is a momentous mutual opportunity for the development of CHI evaluation methodologies and for bringing technical CHI expertise to bear on societal issues.
2269827
Training wheels in a user interface
New users of high-function application systems can become frustrated and confused by the errors they make in the early stages of learning. A training interface for a commercial word processor was designed to make typical and troublesome error states “unreachable,” thus eliminating the sources of some new-user learning problems. Creating a training environment from the basic function of the system itself afforded substantially faster learning coupled with better learning achievement and better performance on a comprehension post-test. A control group spent almost a quarter of their time recovering from the error states that the training interface blocked off. We speculate on how this training strategy might be refined, and more generally, on how function should be organized in a user interface.
14983459
Fixed vs. Dynamic Sub-Transfer in Reinforcement Learning
We survey various task transfer methods in Qlearning and present a variation on fixed sub-transfer which we call dynamic sub-transfer. We discuss the benefits and drawbacks of dynamic sub-transfer as compared with the other transfer methods, and we describe qualitatively the situations where this method would be preferred over the fixed version of sub-transfer. We test this method against several other transfer methods in a simple three room grid world where portions of the source’s policy are relevant to the target task and other portions are not. In this situation we found that dynamic sub-transfer converged to the optimal solution, avoiding the suboptimality inherent in fixed sub-transfer, while also avoiding some of the convergence problems often experienced by fixed sub-transfer.
12738746
Software support for practical grammar development
Even though progress in theoretical linguistics does not necessarily rely on the construction of working programs, a large proportion of current research in syntactic theory is facilitated by suitable computational tools. However, when natural language processing applications seek to draw on the results from new developments in theories of grammar, not only the nature of the tools has to change, but they face the challenge of reconciling the seemingly contradictory requirements of notational perspicuity and efficiency of performance. In this paper, we present a comparison and an evaluation of a number of software systems for grammar development, and argue that they are inadequate as practical tools for building wide-coverage grammars. We discuss a number of factors characteristic of this task, demonstrate how they influence the design of a suitable software environment, and describe the implementation of a system which has supported efficient development of a large computational grammar of English.
14287805
A Formalism and Environment for the Development of a Large Grammar of English
Natural language grammars with large coverage are typically the result of many person-years of effort, working with clumsy formalisms and sub-optimal software support for grammar development. This paper describes our approach to the task of writing a substantial grammar, as part of a collaboration to produce a general purpose morphological and syntactic analyser for English. The grammatical formalism we have developed for the task is a metagrammatical notation which is a more expressive and computationally tractable variant of Generalized Phrase Structure Grammar. We have also implemented a software system which provides a highly integrated and very powerful set of tools for developing and managing a large grammar based on this notation. The system provides a grammarian with an environment which we have found to be essential for rapid but successful production of a substantial grammar.
9629533
The Automatic Acquisition of Verb Subcategorisations and Their Impact on the Performance of an HPSG Parser
We describe the automatic acquisition of a lexicon of verb subcategorisations from a domain-specific corpus, and an evaluation of the impact this lexicon has on the performance of a “deep”, HPSG parser of English. We conducted two experiments to determine whether the empirically extracted verb stems would enhance the lexical coverage of the grammar and to see whether the automatically extracted verb subcategorisations would result in enhanced parser coverage. In our experiments, the empirically extracted verbs enhance lexical coverage by 8.5%. The automatically extracted verb subcategorisations enhance the parse success rate by 15% in theoretical terms and by 4.5% in practice. This is a promising approach for improving the robustness of deep parsing.
8531327
Towards automatic shaping in robot navigation
Shaping is a potentially powerful tool in reinforcement learning applications. Shaping often fails to function effectively because of a lack of understanding about its effects when applied in reinforcement learning settings and the use of inadequate algorithms in its implementation. Due to these difficulties current shaping techniques require some form of manual intervention. We examine some of the principles involved in shaping and present a new algorithm for automatic transferral of knowledge, which uses the Q-values established in a previous task to guide exploration in the learning of a new task. This algorithm is applied to two different but related robot navigation tasks.