There are some information providers whose services are available through the Internet but require payment in order to be used: Dialog, JSTOR, EbscoHost, UMI ProQuest, SilverPlatter, Wilson Index, America Online, etc
In the "old" days, there was the MEDLARS family of databases, DIALOG, and BRS. Since then the MEDLARS databases have gotten bigger, DIALOG has gotten more expensive, and BRS has gone out of business. There are also a growing number of newcomers on the block who provide similar information services. Generally speaking, all these services are more authoritative, offer superior searching mechanisms, and index more specific subject areas than their Internet counterparts. Of course this extra level of service does not come for free.
This section reviews a numbers of these services in terms of their strengths/weaknesses as well as their advantages/disadvantages.
FEE-BASED SERVICES
Title: America Online
Remote HTML
Cost: $1-10
Ease of use: Mindless
Data types: bibliographic citations; full-text articles; ASCII text files; image files;
Search features: field searching; Boolean logic; phrase searching; truncation/stemming;
Description: Don't overlook America Online (AOL) as a potential source of your online information. This commerical service is geared for the masses and therefore fits best into a public library sort of collection. At the same time, the sorts of information available through AOL's services are quite impressive, especially considering the cost: reference materials in all subject areas, (maga)zines of all types, microcomputer software that's easy to find, and business information galore. The services on AOL are well documented online as well as in books. The interface represents the simplest around. The search features vary from service to service within AOL, and while they are adequate, the do not offer very much for the "power user."
Title: JSTOR
Remote HTML
Cost: $ Thousands
Ease of use: Easy
Data types: full-text articles;
Search features: Boolean logic; truncation/stemming; phrase searching; nested queries; proximity; field searching; date ranges; relevance ranking;
Description: This service is unique among all the other services reviewed here in that it provides full-text access to older materials instead of newer materials. Furthermore, since this service represents a non-profit organization, emphasis seems to be on cost-recovery as opposed to excessive profit. The search engine provides the usual features plus a bit of relevance ranking. The titles in the database are, for the most part, for the liberal arts researcher. The images produced from the service's scans are of high quality and more than readable online. JSTOR is filling a much needed niche in the bibliographic database world.
Title: Northern Light Search
Remote HTML
Cost: $1-10
Ease of use: Easy
Data types: bibliographic citations; HTML files; full-text articles;
Search features: phrase searching; truncation/stemming;
Description: This a newcomer into the fray of Internet search engines. Like the resources described in the article "Searching the Hidden Internet" by Notess, this search engine not only provides access to a database of broad WWW documents, but articles from selected magazines and journals (Special Collections) as well. Presently the search features are weak. On the other hand, this engine analyzes the results of queries and creates groups of documents, clusters, much in the same way AltaVista searches are "refined." When you locate a document in the Special Collection you are interested in, you can pay as you go for the article or set up an account. Presently, articles range in price from $0-10 per copy.
Title: Ovid
Remote HTML
Ease of use: Challenging
Data types: bibliographic citations; full-text articles;
Search features: Boolean logic; field searching; truncation/stemming; wild card; proximity;
Description: Using the BRS search software underneath, Ovid is providing bibliographic and full-text access to a number of databases. The search engine, like just about everybody else, is divided into basic and advanced modes. In either case you can specify BRS queries. Like other services, you can browse and seach the authority indexes. Unlike a few of the services, free-text searches can be mapped to controlled vocabulary terms for higher precision/recall ratios. An extra nice part of this service is its abilityi to output it results into formats that are easily imported by personal bibliographic utilities. Ovid also offers the ability to search other database using the search strategies of previous queries.
Title: SilverPlatter
Remote HTML
Data types: full-text articles; bibliographic citations;
Search features: Boolean logic; date ranges; field searching; nested queries; phrase searching; proximity; truncation/stemming; wild card;
Description: SilverPlatter offers sets of bibliographic databases for leasing. These databases can be accessed locally on your computer or remotely on theirs. These databases can also be accessed using any one or a number of client applications for Windows, Macintosh, Unix, or Web browsers. It supports the usual compliment of search features and only lacks the relevance ranking features of the more popular Internet search engines. On the other hand, the ability to browse authority indexes makes for higher precision/recall ratios.
Author: Ebsco
Title: EbsoHost
Remote HTML
Data types: bibliographic citations; full-text articles;
Search features: Boolean logic; field searching; nested queries; date ranges; truncation/stemming; wild card;
Description: Ebsco seems to branching out from it traditional jobber services into this bibliographic and full-text index. After all, they probably had a lot of this data to begin with. The service offers the usual suspects when it comes to searching. It is nice to be able to browse the authority indexes. Ebsco has put together a collection of library-related titles for browsing and searching in order to demonstrate its product. Try also The Library Reference Center at
Author: H. W. Wilson
Title: WilsonWeb
Remote HTML
Ease of use: Easy
Data types: bibliographic citations; full-text articles;
Search features: Boolean logic; date ranges; field searching; nested queries; phrase searching; proximity; truncation/stemming; wild card;
Description: WilsonWeb is the collection of H.W. Wilson indexes and abstracts made available via SilverPlatter ERL database search engine. Consequently, it has all the same search features as the SilverPlatter line of products.
Author: IAC
Title: InofTrac SearchBank
Remote HTML
Ease of use: Difficult
Data types: bibliographic citations; full-text articles;
Search features: Boolean logic; wild card; field searching;
Description: Dispite the fact that this is the publisher of some very popular bibliographic indexes, this service is a bit difficult to use. The query language is obtuse. The advanced search is not that advanced. Queries returned unexplained results, and there aren't very many options for creating queries. Weak. Especially compared to other choices.
Author: Knight-Ridder
Title: DIALOG@Carl
Remote HTML
Ease of use: Easy
Data types: bibliographic citations; full-text articles; news;
Search features: Boolean logic; date ranges; field searching; proximity; truncation/stemming; wild card;
Description: DIALOG@Carl provides "kinder, gentler" interface to a subset of the DIALOG family of databases. Using the simple search feature you enter a controlled vocabulary term, keyword, or phrase and the engine searches for the query terms in its default indexes. That's about it for the simple search. The advanced search allows you to more exactly specify what fields to search as well as supplying date ranges, output numbers, and whether or not you want to limit your search to full-text items. A very nice feature of this service is its ability to search multiple databases simultaneously. To make this even easier, DIALOG@Carl has divided its databases into subject area for searching. Another nice feature "automagically" allows you to search other databases using the query from the previous search.
Author: Knight-Ridder
Title: DialogWeb
Remote HTML
Cost: $ Hundreds
Ease of use: Difficult
Data types: bibliographic citations; full-text articles; news;
Search features: Boolean logic; date ranges; field searching; nested queries; proximity; truncation/stemming; wild card;
Description: This URL points to a Web-based interface to the DIALOG family of databases. The service includes all the features of command-line searching of any DIALOG database plus a few other features. Furthermore, the online help is some of the best around. Somebody did a really good job of porting the command-line interface to a HTML environment. This access method may even be lesser expensive than traditional DIALOG searching since every command is immediately followed by a "seach hold" command. With this interface you have access to more than 450 databases of all types. But this power and flexibility comes at a cost, a rather steep cost. Sign-up fees are around $250 per account and there is an almost $150 annual charge just to keep the password. Database rates are around $45/hour + a couple dollars for each full-text record downloaded. At the same time, the wealth of informaiton found in DIALOGWeb may be what a professional information seeker really needs. Let's hope they know the command syntax!
Author: OCLC
Title: FirstSearch
Remote HTML
Ease of use: Easy
Data types: bibliographic citations; full-text articles; directories;
Search features: Boolean logic; field searching; phrase searching; proximity; truncation/stemming;
Description: This service provides access to an unusual array of bibliographic, full-text, and directory indexes. Like everybody else, it supports a simple searhc as well as a power search. The power search, like everybody else, explodes out various fields making it possible to create more elaborate queries. Like the other services, FirstSearch has divided its collection of databases into subject areas hopefully making it easier for patrons to locate the best database for their particular need. Unlike some of the other services, you can not search more than one database at a time, nor can you save searches between database selections.
Author: UMI
Title: ProQuest Direct
Remote HTML
Ease of use: Easy
Data types: bibliographic citations; full-text articles;
Search features: Boolean logic; proximity; phrase searching; wild card; field searching; ranges; nested queries; "concept extraction"; spelling options;
Description: This service provides the "full meal deal" with one search field interface; there is not power search feature with mulitple input fields. To specifiy field searching you enter the field name you want to search and then the term inside paretheses. It is pnumonic. The Search Assistant is a nice feature where it queries you for term and qualifiers and then builds a search strategy for you.