44645486
Binding objects to scenarios of use
Abstract Scenarios are a natural and effective medium for thinking in general and for design in particular. Our work seeks to develop a potential unification between recent scenario-oriented work in object-oriented analysis/design methods and scenario-oriented work in the analysis/design of human-computer interaction. We illustrate this perspective by showing: (1) how scenario questioning can be used to systematically interrogate the knowledge and practices of potential users, and thereby to create object-oriented analysis models that are psychologically valid; (2) how depicting an individual object's point-of-view can serve as a pedagogical scaffold to help students of object-oriented analysis see how to identify and assign object responsibilities in creating a problem domain model; and (3) how usage scenarios can be employed to motivate and coordinate the design implementation, refactoring and reuse of object-oriented software.
148806746
Human-computer interaction: psychology as a science of design.
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.
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.
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.
5584278
Reinforcement Learning Task Clustering
1970300
Acting out the future: a process for envisionment
It is difficult to design innovative information and communication technologies to meet needs that will emerge from future interactions between users, technologies and their situations of use. We have been using scenarios that are acted out as a way of envisioning the future. This paper describes some of the core dilemmas of innovative design. It draws on our existing work as well as ideas from a range of disciplines to present a ‘light’ but useful envisionment process that may be applied to commercial design problems.
11155402
The effect of failure and repair distributions on consistency protocols for replicated data objects
The accessibility of vital information can be enhanced by replicating the data on several sites, and employing a consistency control protocol to manage the copies.
Various protocols have been proposed to ensure that only current copies of the data can be accessed. The effect these protocols have on the accessibility of the replicated data is investigated by simulating the operation of the network and measuring the performance. Several strategies for replica maintenance are considered, and the benefits of each are analyzed. The details of the simulations are discussed. Measurements of the reliability and the availability of the replicated data are compared and contrasted.
The sensitivity of the Available Copy and Dynamic-linear Voting protocols to common patterns of site failures and repairs is studied in detail. Exponential, Erlang, uniform, and hyperexponential distributions are considered, and the effect the second moments have on the results is analyzed. The relative performance of competing protocols is shown to be only marginally affected by non-exponential distributions, validating the robustness of the exponential approximations.
5978989
Asymmetry in Parsing and Generating with Unification Grammars: Case Studies from ELU
Recent developments in generation algorithms have enabled work in unification-based computational linguistics to approach more closely the ideal of grammars as declarative statements of linguistic facts, neutral between analysis and synthesis. From this perspective, however, the situation is still far from perfect; all known methods of generation impose constraints on the grammars they assume.We briefly consider a number of proposals for generation, outlining their consequences for the form of grammars, and then report on experience arising from the addition of a generator to an existing unification environment. The algorithm in question (based on that of Shieber et al. (1989)), though among the most permissive currently available, excludes certain classes of parsable analyses.
14652639
Ambiguity Packing in Constraint-based Parsing Practical Results
We describe a novel approach to 'packing' of local ambiguity in parsing with a wide-coverage HPSG grammar, and provide an empirical assessment of the interaction between various packing and parsing strategies. We present a linear-time, bidirectional subsumption test for typed feature structures and demonstrate that (a) subsumption- and equivalence-based packing is applicable to large HPSG grammars and (b) average parse complexity can be greatly reduced in bottom-up chart parsing with comprehensive HPSG implementations.