Effective Online Searching

A Basic Text

Christine L. Borgman, Dineh Moghdam, Patti K. Corbett

• Publisher: CRC Press
• Year: 2021
• eBook ISBN: 9781000447668
• Edition: 1
• Topic: Business
• Subtopic: Digital Marketing
• Index: Business

This book focuses on searching and hands-on experience, which makes the text suitable for those who wish to learn searching for their own use as well. It is intended for those who will act as search intermediaries, accepting questions from clients and performing the searches.

1
An Overview of Online Information Retrieval Systems

As the amount of published information has grown, traditional methods of storage and retrieval have diminished in effectiveness. At the same time that the problems of this "information explosion" were being recognized, electronic computers were beginning to influence almost every aspect of our lives.

Prior to 1970, however, little public use was made of computerized online information retrieval systems. These systems were in their infancy. They were difficult and expensive to use, and the information available for searching was limited. In just a few years, tremendous increases in both the speed and memory capabilities of computers, along with a dramatic reduction in their cost, made it feasible to store large volumes of information in computerized form. As a result of these technological improvements and the increased availability of computerized data, online information retrieval systems have become a valuable and convenient tool for libraries and information centers.

Online information retrieval systems provide rapid access to a broad range of information at a low cost. Libraries and information centers around the world are finding such systems indispensable to everyday reference services. Several major vendors provide ready access to hundreds of databases containing a wide range of materials. The individual records in some databases may be references to journal articles, technical reports, patents, books, conference papers, annual reports, trade publications, newspaper and magazine articles, standards and specifications, government documents, theses and dissertations, abstracts and bibliographies, and the like. These databases cover most areas of recorded knowledge, and are especially strong in science and technology. Records in other databases may be source data such as economic and financial time series, corporate earnings, chemical properties, laws, survey data, statistics, or any other data that might be retrieved or manipulated (1).

No single library is capable of housing this large volume of material. Even if it could, access would be cumbersome and time consuming. Online systems provide access to this range of information with a minimum of financial investment and a simple but powerful form of access. It is little wonder that these systems are causing major changes in the way libraries collect, retrieve, and disseminate information.

WHAT IS AN ONLINE INFORMATION RETRIEVAL SYSTEM?

An online information retrieval system is a set of computer hardware and computer software for retrieving information from databases. Computer hardware is the physical equipment of the computer system, such as the computer itself, various storage devices, and terminals. Computer software is the group of programs and procedures that act as instructions to the computer system. A computer terminal is a device similar to a typewriter, with a standard keyboard and a few extra keys for communicating with the computer. It includes either a printer or a television-like screen for displaying information, also known as a VDT (video display terminal) or a CRT (cathode ray tube). The terminal sends and receives information to and from the computer over a communication channel such as a telephone line.

As used in this text, database refers to a collection of related information that is computer-readable, i.e., capable of being interpreted by a computer system. Databases may be divided roughly into two categories: bibliographic (containing references to literature) and nonbibliographic (everything else). Bibliographic databases are the computerized equivalent of indexing and abstracting services. Nonbibliographic databases contain source data which may be either numerical or representational in form. The information that describes the document in the database is known as a document surrogate or unit record. The original data item is called the document, and the set of information that can be retrieved from a database is referred to simply as a record.

The information retrieval systems discussed in this text are both online and interactive. An online system is one in which the user is in direct communication with the computer through a terminal. In an interactive system, the user and the computer engage in two-way communication and the response time by the computer is essentially immediate. Interactive systems are also known as conversational systems.

THE INFORMATION NETWORK

In one sense, the information retrieval process consists simply of a person sitting at a computer terminal interacting with a computer system. In a larger context, the person and the computer system are components of an information network, or a set of interconnected technologies and organizations. Visualizing the information retrieval process as an information network provides a perspective on how all of the pieces fit together (see Figure 1.1).

When a person searches an information retrieval system, he or she is utilizing a computer terminal, a telecommunications network (usually consisting of telephone lines) for connecting the terminal to the computer, the computer itself, the software or searching programs, and one or more databases. All of these components of the information network are used simultaneously when searching an information retrieval system, yet each of them may be supplied by a different company or organization.

DATABASE PRODUCERS

Database producers are the organizations that collect the information, select appropriate documents or other items for inclusion in the database, and convert the material into computer-readable form. The database producers analyze the documents, extract important information such as the author, title, and source of publication (for bibliographic databases), and may augment the extracted information with additional information such as index terms, abstracts, language codes, or chemical structures.

Figure 1.1

Figure 1.1. An information network.

In the case of bibliographic databases, producers typically subscribe to the journals which are covered by the database, collect other types of literature for inclusion, and index and abstract the materials selected (2). In some cases the selected documents may be both indexed and abstracted; in others they may only be indexed; or they may be neither indexed nor abstracted. For nonbibliographic databases, some indexing or other method of augmenting the records may be required. Conversion to computer-readable form normally requires keying (typing) the records into a computer (e.g., via a terminal) which can convert them to a computerzied format. The records are then stored in mass storage devices such as magnetic tapes or disks (3).

Database producers exist in the public, private, and government sectors of the economy. Public sector database producers are frequently professional societies such as the American Psychological Association or the American Society for Metals. An increasing number of databases are produced by private, for-profit organizations such as the Institute for Scientific Information, Predicasts, Dow Jones, and The New York Times. Government organizations were among the first to generate publicly available databases. There are several prominent government-supported databases such as those produced by the National Library of Medicine and the National Library of Agriculture, and the ERIC (Educational Resources Information Center) database which is produced by several resource centers under government contract.

Many bibliographic databases are the computer-readable counterpart of printed indexing and abstracting services such as ERIC, Psychological Abstracts, and Science Citation Index. Most of the older databases began as "print tapes" used for typesetting the printed versions. More recently, bibliographic databases have been developed that are available only in computer readable form, with no printed equivalent available for purchase.

In some cases, database producers may also provide computer access to the databases. Typically, however, databases are leased to the organizations that support the computer services and the searching software. These organizations--called search service vendors--usually pay royalty fees to the database producer for the amount of time the database is in use.

SEARCH SERVICE VENDORS

Search service vendors are the organizations that own the computers and the software for information retrieval. These vendors have developed standardized sets of instructions or commands for searching (also known as search protocol), as well as software to manipulate the databases.

Vendors either lease databases from database producers or generate their own, in which case they also become database producers. Several large search service vendors lease multiple databases--as many as 100 or more--and make them available with a common search protocol. A number of specialized single database search services are in the market as well. However, as most searching is done through the large systems, they are the primary focus of this text.

Search service vendors usually receive databases from the database producers on magnetic tapes which are then loaded into the vendor's computer system. Processing the tapes includes generating indexes and various access points to the database. The same database may be leased to more than one vendor, in which case there may be differences in the way the data are formatted and the indexes structured, as well as how the database is searched.

Most search service vendors maintain some output or printing capability at the computer site. Users needing a large number of records from a search have the option of printing them at the vendor's computer site (known as offline printing) and having them mailed.

The search service computer system has an accounting subsystem which monitors the amount of time that individual terminals and specific searchers are connected to the computer system, how much time is spent searching each database, and the amount of offline printing that is done. All of these items, and perhaps some others, are included in the charges for the use of the search service.

TELECOMMUNICATIONS NETWORKS

Most connections to search service computer systems are made through telecommunications networks known as "value-added networks," or VANs. The two VANs most commonly used on this continent are TYMNET and TELENET, although others are appearing on the market. These networks generally consist of sets of leased telephone lines connected with minicomputers controlling the lines in each major service area. Network access is available on other continents as well.

To use one of the networks, the searcher makes a telephone call to the computer at the nearest access point (or network node) and connects the telephone to the computer terminal. The searcher keys a command into the terminal to identify the terminal to the network and then requests the desired search system. The network makes the link between the terminal and the appropriate computer. Charges for the use of the network are billed by the search service vendor, with a "value added" for the use of the telecommunications network,

THE ROLE OF THE SEARCHER

The final link in the information network is the searcher, who utilizes all of the other components simultaneously. He or she usually accesses the information retrieval system through a computer terminal located in a library or information center. The searcher could also be an executive with a portable terminal in a hotel room, a researcher in a laboratory, or a person searching in any of a wide variety of situations. Since the use of these online information retrieval systems requires a considerable amount of training, most searching is done by specialists employed by libraries or information centers. These specialists perform searches for other persons who have particular information needs or requests. In this text, searcher, search analyst, or search intermediary refers to the person who actually performs the search and interacts with the information retrieval system. Client or requester refers to the person making the information request.

The searching process begins with the information need or request. This request is expressed to the searcher, who will structure it into a search strategy, a special format that can be understood by the information retrieval system. The searcher determines the appropriate search system and database most likely to satisfy the information need.

The searcher turns the computer terminal on, makes a telephone call to the telecommunications network, and requests the appropriate search system computer. Once the connection to the computer has been made, the searcher requests the desired database. He or she keys the search strategy on the terminal and sends it to the computer. The computer responds with the results of the search (the number of records found or the source data requested). The results may be printed on the terminal, on a printer in the library, or offline at the search service computer site. The searcher also has the option of making changes in the search strategy or choice of databases and of performing additional searches. This process continues until satisfactory results are obtained.

When the search has been finished, the searcher keys a command to exit from the system. This command disconnects the terminal both from the telecommunications network and the search service computer. The searcher hangs up the telephone and turns the terminal off, thus completing the searching process.

HISTORICAL DEVELOPMENT OF ONLINE INFO...

Table of contents

• Cover
• Half Title
• Series Page
• Title Page
• Copyright Page
• Dedication
• Contents
• Foreword
• Preface
• Acknowledgments
• 1 AN OVERVIEW OF ONLINE INFORMATION RETRIEVAL SYSTEMS
• 2 CHARACTERISTICS OF A GOOD SEARCHER
• 3 PREPARING TO SEARCH
• 4 SEARCH STRATEGY CONSTRUCTION
• 5 CONDUCTING THE ONLINE SEARCH
• 6 DATABASES
• 7 VOCABULARY CONTROL
• 8 ADVANCED SEARCHING TECHNIQUES
• 9 PERFORMANCE MEASUREMENT AND EVALUATION
• 10 EQUIPMENT CONSIDERATIONS
• 11 SOURCES OF TRAINING
• Index