Information retrieval and hypertext: competing technologies or complementary access methods

Abstract. Information retrieval typically involves accessing textual information from a database in response to a user's vague information need. Hypertext or hypermedia, on the other hand, involves a user browsing through a database of textual or multimedia information in response to a variety of types of information need. Thus information retrieval can be said to have a searching metaphor while hypertext has a browsing analogy. Initially, these two technologies for information access appear to be very different, almost competitive in nature. In this paper information retrieval systems are briefly reviewed and hypertext systems are also examined. These two techniques for accessing information have been integrated into a prototype system which is described. The system dynamically generates guided tours in response to a user's query and the tour guides the user through the hypertext. Some experiments reporting on the effectiveness of this as an information access strategy are given.     

Review: An information management system for informal design data

Engineering information management may be divided into formal information management, which involves data modelling, data exchange and transaction handling, and informal information management, which is concerned with the organisation and delivery of design advice and design parameter data. This paper describes a system, called Review, which has been developed for the management of informal design information from multiple sources. The system uses a hybrid hypertext/database approach to provide for the indexing and viewing of information sources using arbitrary attribute sets, and for the establishment of relationships between information entities using both static and dynamic links in a hypertext framework. Information may be accessed both by query and by browsing along relationships in the hypertext network. The paper presents an overview of the system design, and examples of its application to design advisory systems and documentation.     

Incorporating String Search in a Hypertext System: User Interface and Signature File Design Issues

Hypertext systems provide an appealing mechanism for informally browsing databases by traversing selectable links. However, in many fact finding situations string search is an effective complement to browsing. This paper describes the application of the signature file method to achieve rapid and convenient string search in small personal computer hypertext environments. The method has been implemented in a prototype, as well as in a commercial product. Performance data for search times and storage space are presented from a commercial hypertext database. User interface issues are then discussed. Experience with the string search interface indicates that it was used successfully by novice users.     

Introduction

We describe an SQL relational database schema for representing the objects in HyperCard, along with a technique for automatically populating this schema from a HyperCard stack using the facilities in HyperTalk with calls to the database manager. The standard relational database query language SQL can then be used to perform more general hypertext searches than are possible with the string search feature found in most hypertext browsing environments. Semiautomatic updates of the content of a hypertext are also possible using SQL updates on the object representations in the database to trigger corresponding HyperCard updates on the objects themselves. We describe a prototype implementation and present several example queries and updates to motivate this approach. These techniques, although demonstrated here specifically using HyperCard and Oracle for Macintosh, are generally applicable to a wide range of hypertext systems and relational databases.     

一个基于CORBA的异构数据源集成系统的设计

提出一个基于CORBA(common object request broker architecture)的即插即用的异构多数据源集成系统的设计方案.由于采用具有较强描述能力的OIM(object model for integration)对象模型作为集成系统的公共数据模型,该系统不仅能集成各种异构数据源,包括数据库系统、文件系统、WWW上HTML文件中的数据,而且能集成随时插入的新数据源中的数据.着重讨论系统的总体结构、OIM对象模型、查询处理及界面设计.     

A Model for Query Decomposition and Answer Construction in Heterogeneous Distributed Database Systems

The problem of retrieving information from a collection of heterogeneous distributed databases has attracted a number of solutions. However, the task of integrating established database systems is complicated not only by the differences between the database systems themselves, but also by the differences in structure and semantics of the information contained within them. The problem is exacerbated when one needs to provide access to such a system for naive end-users.This paper is concerned with a Knowledge-Based Systems approach to solving this problem for clearly bounded situations, in which both the domain and the types of query are constrained. At the user interface, dialogue is conducted in terms of concepts with which the user is familiar, and these are then mapped into appropriate database queries. To achieve this a model for query decomposition and answer construction has been used. This model is based around the development of an Intensional Structure containing information necessary for the recapture of semantic information lost in the query decomposition process and required in the answer construction process. The model has been successfully implemented in combination with an embedded KBS, within a five-layer representation model.     

Browsing large online data tables using generalized query previews

Companies, government agencies, and other organizations are making their data available to the world over the Internet. They often use large online relational tables for this purpose. Users query such tables with front-ends that typically use menus or form fillin interfaces, but these interfaces rarely give users information about the contents and distribution of the data. Such a situation leads users to waste time and network/server resources posing queries that have zero- or mega-hit results. Generalized query previews enable efficient browsing of large online data tables by supplying data distribution information to users. The data distribution information provides continuous feedback about the size of the result set as the query is being formed. Our paper presents a new user interface architecture and discusses three controlled experiments (with 12, 16, and 48 participants). Our prototype systems provide flexible user interfaces for research and testing of the ideas. The user studies show that for exploratory querying tasks, generalized query previews can speed user performance for certain user domains and can reduce network/server load.     

Hypertext Access and the New Oxford English Dictionary

While hypertext access to the New Oxford English Dictionary would seem to be potentially beneficial, the conversion of such a text to a hypertext document and the generation of semantic links may not be feasible. Rather than attempting either the conversion of the text or the designation and storage of specific hypertext links, a prototype frontend called READER has been developed that provides hypertext access to the Dictionary. The emphasis in this work has been to provide the user with the browsing approach typical of hypertext rather than the more traditional query-oriented approach to accessing full-texts. The prototype is based on a dynamic hypertext model which facilitates browsing through the dynamic instantiation of implicit links existing in the text of the Dictionary.     

WebDB: A System for Querying Semi-structured Data on the Web

The World-Wide Web can be viewed as a collection of semi-structured multimedia documents in the form of Web pages connected through hyperlinks. Unlike most web search engines, which primarily focus on information retrieval functionality, WebDB aims at supporting a comprehensive database-like query functionality, including selection, aggregation, sorting, summary, grouping, and projection. WebDB allows users to access (1) document level information, such as title, URL, length, keywords types and last modified date; (2) intra-document structures, such as tables, forms and images and (3) inter-document linkage information, such as destination URLs and anchors. With these three types of information, comprehensive queries for complex Web-based applications, such as Web mining and Web site management, can be answered. WebDB is based on object-relational concepts: Object-oriented modeling and relational query language. In this paper, we present the data model, language and implementation of WebDB. We also present the novel visual query/browsing interface for semi-structured Web and Web documents. Our system provides high usability compared with other existing systems.     

Automatic generation and refinement of hypertext links

Abstract

Current generation of hypertext systems suffer from the limitations that they are static in nature, and they do not support the automated process of link creation very well. Because of the efforts involved in manually creating links, the hyperbases created using these systems are seldom modified even when they were found not to fully support the requirements of the intended users. This paper studies the development of automated tools to aid in the process of link creation, browsing, and link refinement. Only relation links are considered in this study. The automated tools are developed to help in three of the major stages of developing and using hypertext applications: (a) during authoring to generate a set of relation links between pairs of nodes; (b) during browsing to recommend an optimal set of starting nodes for the users to begin browsing, and to guide the users at each stage of browsing by suggesting a set of “next” nodes to traverse; and, (c) during training to modify, remove and add links based on users' feedback data collected. The training will result in long-term changes in the hypertext structure.

In order to test the effectiveness of the training process objectively, a navigator is built to simulate the browsing activities of the users. The effects of training have been evaluated on two text collections using a variety of objective measures. The results indicate that the training process has improved the effectiveness of the hyperbase to support browsing.     

Exploring spatial datasets with histograms

As online spatial datasets grow both in number and sophistication, it becomes increasingly difficult for users to decide whether a dataset is suitable for their tasks, especially when they do not have prior knowledge of the dataset. In this paper, we propose browsing as an effective and efficient way to explore the content of a spatial dataset. Browsing allows users to view the size of a result set before evaluating the query at the database, thereby avoiding zero-hit/mega-hit queries and saving time and resources. Although the underlying technique supporting browsing is similar to range query aggregation and selectivity estimation, spatial dataset browsing poses some unique challenges. In this paper, we identify a set of spatial relations that need to be supported in browsing applications, namely, the contains, contained and the overlap relations. We prove a lower bound on the storage required to answer queries about the contains relation accurately at a given resolution. We then present three storage-efficient approximation algorithms which we believe to be the first to estimate query results about these spatial relations. We evaluate these algorithms with both synthetic and real world datasets and show that they provide highly accurate estimates for datasets with various characteristics. Recommended by: Sunil Prabhakar Work supported by NSF grants IIS 02-23022 and CNF 04-23336. An earlier version of this paper appeared in the 17th International Conference on Data Engineering (ICDE 2001).     

SEE: a Spatial Exploration Environment based on adirect-manipulation paradigm

The need to provide effective tools for analyzing and querying spatial data is becoming increasingly important with the explosion of data in applications such as geographic information systems, image databases, CAD, and remote sensing. The SEE (Spatial Exploration Environment) is the first effort at applying direct-manipulation visual information seeking (VIS) techniques to spatial data analysis by visually querying as well as browsing spatial data and reviewing the visual results for trend analysis. The SEE system incorporates a visual query language (SVIQUEL) that allows users to specify the relative spatial position (both topology and direction) between objects using direct manipulation. The quantitative SVIQVEL sliders (S-sliders) are complemented by the qualitative active-picture-for-querying (APIQ) interface that allows the user to specify qualitative relative position queries. APIQ provides qualitative visual representations of the quantitative query specified by the S-sliders. This increases the utility of the system for spatial browsing and spatial trend discovery with no particular query in mind. The SVIQUEL queries are processed using a k-Bucket index structure specifically tuned for incremental processing of the multidimensional range queries that represent the class of queries that can be expressed by SVIQUEL. We have also designed a tightly integrated map visualization that helps to preserve the spatial context and a bar visualization that provides a qualitative abstraction of aggregates     

Retrieving information from hypertext: issues and problems

One of the most important developments in information science and in information systems in recent years has been the emergence of hypertext as a way of organizing information. Hypertext uses a browsing rather than a searching strategy and hypertext systems have found applications in a number of diverse areas. One of the strengths of using a hypertext system is the freedom it gives to users in the choice of information they wish to see, but this is also one of its drawbacks. This paper examines the effectiveness of hypertext as a way of retrieving information and reviews conventional information retrieval techniques which are the alternative strategy. Previous attempts at combining information retrieval and hypertext are considered and a prototype system outlined which has been developed to generate guided tours for users, to direct them through a hypertext to information they have requested. Finally, how adding this kind of intelligent guidance to a hypertext system would affect its usability as an information system is discussed.     

基于内容的多媒体数据库系统引擎CDB

CDB(Content-based DataBase)是一种基于内容的多媒体数据库引擎，可以嵌入到通用的对象一关系数据库中，使数据库系统综合支持对多媒体数据的常规和基于内容的壹询．本文首先阐述CDB的体系结构，它把信息检索和数据检索结合到数据库中，支持多媒体数据库的基于内容的建立、操纵和维护；然后给出其层次型内容模型，描述多媒体内容的时空结构特征以及信息线索；最后描述用于CDB的基于内容信息检索技术及其设计和实现的用户壹询和操纵接口，包括示例壹询、主观颜色壹询、视频概要和浏览、扩展SQL内容壹询等．     

Information Filtering Using User's Context on Browsing in Hypertext

Browsing is one of the most popular ways to gather information in database with hypertext structure. In order to support a user to browse, modeling of the user's interests is one of the most important issues. Although there are several promising methods to infer the interests from the user's browsing behavior, they assume that the interests are consistent during the browsing. However, the user's interests are often strongly dependent on the local context of the browsing. This paper describes a method to model the user's shifting interests from the browsing history. An information filtering method using the model of the interests has been implemented. We call it ‘context-sensitive filtering’. The results of an experimental evaluation, by real users' browsing for an encyclopedia in CD-ROM format, are also reported. This revised version was published online in July 2006 with corrections to the Cover Date.     

The user interface in a hypertext, multiwindow program browser

The program browsing problem is discussed, with particular emphasis on a multiple-window user interface and its implications for recording acquired knowledge, navigation, and attention-tracking. Hypertext systems are considered as an implementation of browsing techniques for nonprogram text. A classification scheme for text-viewing systems is offered, and then browsing is discussed as a nonintrusive, static technique for program study.

Multiple techniques are synthesised into a coherent plan for a multiwindow program study tool, based on theories of program browsing and the use of hypertext. A test system, HYBROW, emerged from the plan for studying the application of several hypertext multiple-window techniques to program browsing, especially window replacement. HYBROW is a hypertext, multiple-window program browser. This generic tool is applicable to any source language, although certain aspects of the preprocessing and the hierarchical browser presentation are specific to the C language. The tool permits opening an arbitrary number of text windows into an arbitrary number of files, rapid window switching, multiple-window search, placemarking, automatic screen organisation, and services for the creation, maintenance and production of study notes. An informal usability study was conducted.