Dennis Quan

Haystack: a platform for authoring end user semantic web applications

The Semantic Web promises to open innumerable opportunities for automation and information retrieval by standardizing the protocols for metadata exchange. However, just as the success of the World Wide Web can be attributed to the ease of use and ubiquity of Web browsers, we believe that the unfolding of the Semantic Web vision depends on users getting powerful but easy-to-use tools for managing their information. But unlike HTML, which can be easily edited in any text editor, RDF is more complicated to author and does not have an obvious presentation mechanism. Previous work has concentrated on the ideas of generic RDF graph visualization and RDF Schema-based form generation. In this paper, we present a comprehensive platform for constructing end user applications that create, manipulate, and visualize arbitrary RDF-encoded information, adding another layer to the abstraction cake. We discuss a programming environment specifically designed for manipulating RDF and introduce user interface concepts on top that allow the developer to quickly assemble applications that are based on RDF data models. Also, because user interface specifications and program logic are themselves describable in RDF, applications built upon our framework enjoy properties such as network updatability, extensibility, and end user customizability - all desirable characteristics in the spirit of the Semantic Web.

Using semantic web technologies for representing E-science provenance

Life science researchers increasingly rely on the web as a primary source of data, forcing them to apply the same rigor to its use as to an experiment in the laboratory. The Grid project is developing the use of workflows to explicitly capture web-based procedures, and provenance to describe how and why results were produced. Experience within Grid has shown that this provenance metadata is formed from a complex web of heterogenous resources that impact on the production of a result. Therefore we have explored the use of Semantic Web technologies such as RDF, and ontologies to support its representation and used existing initiatives such as Jena and LSID, to generate and store such material. The effective presentation of complex RDF graphs is challenging. Haystack has been used to provide multiple views of provenance metadata that can be further annotated. This work therefore forms a case study showing how existing Semantic Web tools can effectively support the emerging requirements of life science research.

How to make a semantic web browser

Two important architectural choices underlie the success of the Web: numerous, independently operated servers speak a common protocol, and a single type of client the Web browser provides point-and-click access to the content and services on these decentralized servers. However, because HTML marries content and presentation into a single representation, end users are often stuck with inappropriate choices made by the Web site designer of how to work with and view the content. RDF metadata on the Semantic Web does not have this limitation: users can gain direct access to information and control over how it is presented. This principle forms the basis for our Semantic Web browser an end user application that automatically locates metadata and assembles point-and-click interfaces from a combination of relevant information, ontological specifications, and presentation knowledge, all described in RDF and retrieved dynamically from the Semantic Web. Because data and services are accessed directly through a standalone client and not through a central point of access (e.g., a portal), new content and services can be consumed as soon as they become available. In this way we take advantage of an important sociological force that encourages the production of new Semantic Web content while remaining faithful to the decentralized nature of the Web.

The role of context in question answering systems

Despite recent advances in natural language question an-swering technology, the problem of designing effective user interfaces has been largely unexplored. We conducted a user study to investigate the problem and discovered that overall, users prefer a paragraph-sized chunk of text over just an exact phrase as the answer to their questions. Fur-thermore, users generally prefer answers embedded in con-text, regardless of the perceived reliability of the source documents. When users research a topic, increasing the amount of text returned to users significantly decreases the number of queries that they pose to the system, suggesting that users utilize supporting text to answer related ques-tions. We believe that these results can serve to guide future developments in question answering user interfaces.

Haystack: a user interface for creating, browsing, and organizing arbitrary semistructured information

Much past HCI research has examined the usability concerns of information management software for specific domains such as object-oriented software design, e-mail, and the Web. We believe that many of the results uncovered by these studies are applicable across multiple domains but that more broadly-scoped experiments require a system that can integrate multiple data sources. Haystack is a general-purpose information management environment designed to attack this very problem. Haystacks user interface, which incorporates capabilities from previous research such as context-specific visualization paradigms and attribute-based categorization, is built upon a highly expressive semistructured data model and data integration capabilities. In our demonstration we show how combination of a direct-manipulation-based UI paradigm and an expressive, federated data model can begin to address many of the information management problems plaguing general desktop computing today and can serve as a basis for further, yet unexplored, crossover information interaction experiments.

Natural Language Annotations for the Semantic Web

Because the ultimate purpose of the Semantic Web is to help users locate, organize, and process information, we strongly believe that it should be grounded in the information access method humans are most comfortable with--natural language. However, the Resource Description Framework (RDF), the foundation of the Semantic Web, was designed to be easily processed by computers, not humans. To render RDF friendlier to humans, we propose to augment it with natural language annotations, or metadata written in everyday language. We argue that natural language annotations are not only intuitive and effective, but can also accelerate the pace with which the Semantic Web is being adopted. We demonstrate the use of natural language annotations from within Haystack, an end user Semantic Web platform that also serves as a testbed for our ideas. In addition to a prototype Semantic Web question answering system, we describe other opportunities for marrying natural language and Semantic Web technology.

User interface continuations

Dialog boxes that collect parameters for commands often create ephemeral, unnatural interruptions of a programs normal execution flow, encouraging the user to complete the dialog box as quickly as possible in order for the program to process that command. In this paper we examine the idea of turning the act of collecting parameters from a user into a first class object called a user interface continuation. Programs can create user interface continuations by specifying what information is to be collected from the user and supplying a callback (i.e., a continuation) to be notified with the collected information. A partially completed user interface continuation can be saved as a new command, much as currying and partially evaluating a function with a set of parameters produces a new function. Furthermore, user interface continuations, like other continuation-passing paradigms, can be used to allow program execution to continue uninterrupted while the user determines a commands parameters at his or her leisure.

Sticky notes for the semantic web

Computer-based annotation is increasing in popularity as a mechanism for revising documents and sharing comments over the Internet. One reason behind this surge is that viewpoints, summaries, and notes written by others are often helpful to readers. In particular, these types of annotations can help users locate or recall relevant documents. We believe that this model can be applied to the problem of retrieval on the Semantic Web. In this paper, we propose a generalized annotation environment that supports richer forms of description such as natural language. We discuss how RDF can be used to model annotations and the connections between annotations and the documents they describe. Furthermore, we explore the idea of a question answering interface that allows retrieval based both on the text of the annotations and the annotations associated metadata. Finally, we speculate on how these features could be pervasively integrated into an information management environment, making Semantic Web annotation a first class player in terms of document management and retrieval

Haystack: a platform for creating, organizing and visualizing semistructured information

1. OVERVIEW In this demonstration we present Haystack, an environment that allows users to easily manage their documents, e-mail, appointments, tasks, and other information [1]. Haystack uses a semistructured data model to describe the connections between different documents in a user’s corpus as well as the metadata concerning each document. This amalgamation provides users with a unified framework for managing all of their information, e.g., documents, e-mails, etc., through a single interface. Furthermore, Haystack’s user interface exposes general tools for navigating the various kinds of information found in users’ corpora.

Collections: flexible, essential tools for information management

While collections-aggregation mechanisms such as folders, buddy lists, photo albums, etc.-clearly play a central role in information management, the potential benefits of true first class support for collections are masked by disparate implementations that force users to pay attention to technological distinctions such as application, format, and protocol. We argue that systems should expose a single unified concept of collection and that concepts such as portals, cross-application projects, customized menus, and e-mail-task unification come about naturally as a result of our abstraction. In addition, uniform support for collections brings about a new set of capabilities for supporting creative processes. We discuss a prototype implementation of this abstraction in our Haystack system, give several examples of why we believe our abstraction is useful in everyday information management, and present some preliminary results from user studies that support our hypotheses.