Online access to information sources and services
Paul NIEUWENHUYSEN
Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussel, België.

	Tel. 32 - 2 - 629 2436 		Fax 32 - 2 - 629 2693 
	Internet electronic mail address: PNIEUWEN@VUB.AC.BE

In this workshop an overview is presented of contemporary methods to find information through the Internet and the WWW about a particular subject, to support management, decision making, scientific research, journalism and so on. It is hoped to have a lively discussion and some hands-on experience by using the available microcomputers and Internet access.
The following subjects are briefly discussed: 
--dictionaries and encyclopaedias, 
--Internet subject directories for browsing, 
--Internet indexes for full text searching, 
--multi-threaded meta-search systems, 
--finding images and sounds, 
--finding books and journal articles, 
--using electronic journals, 
--using current awareness systems, 
--classical citation searching through the WWW and using citations to WWW pages,
--evaluation of Internet based information sources, 
--evolution and trends in online information services, 
--using computer-based network interest groups.

Because only 90 minutes are available during the actual workshop, participants should ideally come well prepared by experience or by inspecting some of the study materials in the form of slide presentations that may be relevant for this workshop, which are available through the WWW at 
http://www.vub.ac.be/BIBLIO/nieuwenhuysen/courses/chapters/index.html
or by reading some documents that are included in the bibliographies that come with the presentations, and which are also available through the WWW at
http://www.vub.ac.be/BIBLIO/nieuwenhuysen/courses/bibliography/index.html

The participants can raise questions and can express their preference for particular topics to be discussed during the workshop, by sending as soon as possible before the workshop an email message to Paul.Nieuwenhuysen@vub.ac.be

The following gives a brief overview.

Online access information sources and services

Introduction

To discover, find, retrieve and use information online accessible information sources, we need a microcomputer, data communication facilities, tools to locate information sources, and of course some knowledge and skills.
Networked information resources are growing at a high rate, not only in volume but also in importance. There are many sources, which are vital to research, and many others that are useful generally. To keep abreast of their field, most academics and researchers will find an increasing need to use the network for fast and efficient communication and for access to information. If they do not, they are likely to be left behind, because most of their colleagues in institutions around the world will be doing just that.
Nevertheless we see some problems, some difficulties associated with online accessible information:
•	On the one hand, there is too much information on some topics; in other words, the redundancy and overlap are high in many cases. On the other hand, there are too few information sources on some topics.
•	There is no order imposed and quality checks are not performed on most sources. Related to this: it is not required to register new information offered. Is the information that you find real, honest, and authentic? A tutorial in English about how to assess the quality of WWW-based information resources can be accessed online free of charge through the WWW: http://sosig.esrc.bris.ac.uk/desire/internet-detective.html
•	Information sources are constantly changing, growing, but sometimes disappearing.
•	Surfing, using the Internet, the WWW, can become a time sink instead of a productive activity.

At the time of writing this, we can access more than 1 000 million unique addresses in the total Internet. Such an address is indicated in the form of a so-called URL. More than 10 terabyte (= 10 000 gigabyte) of text data are made available in this way.
A lot of the information on the Internet is available free of charge, but another part is only accessible when a fee is paid to the producer and / or the distributor. Some organisations pay these fees for some sources and then organise access, so that the members of the organisation can retrieve and exploit the information as if it is free of charge.
Most of the information that is freely available on the WWW is provided by commercially oriented organisations and thus not objective or scientific in most cases, but even subjective or perhaps even misleading, and attracting more attention than more scientific information. (Of course many information sources are also provided by commercial organisations that belong to the so-called information industry, but these are bound to supply objective information of high quality, as this is their way to survive commercially.)
In the following we focus on various types of information resources that are accessible through the Internet.
Where can we find good and relevant information sources on the Internet? This is not an easy question in view of the difficulties associated with this medium as described above. To find potentially interesting documents and databases that are provided through the WWW, we can use printed manuals and guides or systems offered on the WWW. The printed guides suffer from some disadvantages: it is not always possible to get a copy fast, it costs money to get a copy, and they are soon out of date. On the other hand, the retrieval systems offered on the WWW show advantages: they are directly available from the same microcomputer that we want to use to find information on the Internet, many of these systems are accessible free of charge, and most of these systems are regularly updated.
The search tools available on the WWW to find information on the Internet, belong to two main types, like any retrieval system: those offering an overview that can be browsed and those that require the formulation of a search query.

Internet directories for browsing

The overviews or directories can normally be browsed following a tree structure or a more complicated variation. The structure corresponds to a classification that is normally specific for the particular overview. In other words: the well-known and classical universal classification systems are not used in most Internet directories. They are virtual libraries with open shelves, manually generated, man-made by many co-operating people. Many of these directories include an index to search their contents. However, then the assisting classification structure is not well exploited and the user should be aware of the problems and difficulties of information retrieval with natural language queries. Furthermore, the possibility to use the system in this way may be confusing, as these directories are not real full-text Internet indexes, like those provided by other search tools. The most famous of these directories belong to the most popular and most visited sites on the WWW.
Some examples of such systems at the time of writing this article:
Yahoo! Accessible starting at http://www.yahoo.com/, and at many other sites. At this moment this is a very popular directory. Entries are not rated. The search tool is accessible free of charge. The directory of Yahoo! cannot only be browsed, but can also be searched with a query, although in this way the hierarchical structure is not well exploited. When such a query does not provide results, then Yahoo! uses a much larger external Internet index (not produced by Yahoo!) to execute a query based on textual search statements. The chosen Internet index has varied over time. This mechanism is not made very clear and may confuse the user.
Some similar and competing directories that are also accessible free of charge can be found as a part of the following WWW sites:
•	http://britannica.com/ that is combined and integrated with a great general encyclopaedia
•	http://bubl.ac.uk/
•	http://www.clearinghouse.net/
•	http://magellan.excite.com/
•	http://www.dmoz.org/
•	http://www.lii.org/
•	http://www.looksmart.com/ but this directory can also be accessed from the popular site http://www.altavista.com

Because a complete list of all the global Internet directories cannot be given, because they change over time, and because there are large differences among them, the following gives an overview of possible features and evaluation criteria relevant for these systems:
•Is usage free of charge?
•Wide coverage?
•Up to date? Frequent updates? Only few dead / broken links?
•Good coverage of the sources in that part of the world in which you are interested?
•Does the manager of the directory refuse to give priority to sites that want to pay to get a prominent place in the directory?
•Easy user interface?
•Short response times?
•Good presentation?
•Are mirror sites available closer to you for faster response?
•Is a description, rating, appreciation, review offered for each listed site?
•Is translation of documents offered free of charge?
•Good documentation and online help?
•Good help desk available?
•High stability and reliability?
•Are other services offered from the same site or with the same interface? Is the subject directory integrated with other services? (Additional services can be for instance an Internet index or a WWW index or a gateway to such an index for searching with a query.)
Besides the general global directories, there are directories that focus on the sources in a particular region or country, or on a particular subject domain. Many of these can be found starting from a more general directory.

Searchable Internet indexes

The alternative type of systems to find information on the Internet allow to search for and to locate many items (addressable resources) in the Internet in a more systematic, direct way than by browsing only. Each of these search systems is based on a database of links to pages (URLs) that can be retrieved by searching with queries through a big index that is built (machine-made) on the basis of the contents, the texts, of these pages. To build this database and to keep it up to date, pages are continuously collected from the Internet by a “robot” computer software system. A search system with a user interface in a form on the WWW allows the user to search through that database.
Examples of such Internet search systems can be found at
http://www.altavista.com/
http://www.alltheweb.com/
http://www.excite.com/
http://www.google.com/
http://www.hotbot.com/
http://www.northernlight.com/
http://search.msn.com/
Besides their common aims and characteristics, we can nevertheless see differences among these systems. To illustrate these variations and to assist Internet users to make a decision on which search system to use, the following list of some features and evaluation criteria can be useful.
•Is usage free of charge?
•How complete is the coverage?
•Is the coverage good (or poor) for a particular geographic region?
•Is the coverage good (or poor) for a particular type of documents?
•Is the searchable database up to date? Is the database updated frequently? Do the search results contain only few dead (broken) links?
•Is spamming filtered out, to give other pages a better chance of turning up in the result set? Can the system cluster presumed duplicate documents in the results? Or does the system simply eliminate presumed duplicate documents from its database?
•Does the database system work with a full text indexing of each ASCII and HTML document that has a place in the database, so that full text searching is possible?
•Are the contents of meta-fields also indexed to make them searchable?
•Does the system index also the text in files on the web that consist of non-ASCII codes to make these also searchable and retrievable? (For instance files in the format of the various versions of Microsoft Word, Microsoft PowerPoint, Adobe's Portable Document Format.)
•Does the system offer powerful search options like truncation, word stemming, Boolean search combinations, searching of words occurring close together, automatic translation of your search terms in several other languages, spelling check of your search terms?
•Can the results be limited to a certain time period? (For instance based on the date of the file as noted by the server computer, or of the most recent indexing of the file.)
•Is the user interface easy to understand and efficient to use?
•Is a user interface offered in your own language?
•Does the system rank the items in the result set according to their presumed relevance?
•Does the system offer a good presentation format of each result (document/page/item)? For instance: are search terms indicated / highlighted in the results?

Finding multimedia files on the Internet

To find images (photos, artwork...), sounds (speeches...), animations or video on the Internet, some specialised systems can be used. For instance, when searching for images, the search results from such a system offer not only links to the image files on the Internet, but also directly small versions of the images (so-called “thumbnails”). Some examples of actual systems can be found at
•http://gallery.yahoo.com/
•http://scour.net/
•http://www.altavista.com/ 
•http://www.ditto.com/
•http://www.excite.com/search/photosearch/
•http://www.go.com/

Current awareness services focusing on WWW pages

Tracking changes in one or more public access pages on the WWW is possible for instance through “alert” services based on a server on the WWW that track updates for the user and that send alerts by email to the user. Several of these systems are free of charge, such as 
•	http://informant.dartmouth.edu/
•	http://mindit.netmind.com/
•	http://www.northernlight.com/
Some systems can send you an alert when they have discovered a new document that corresponds to your interest profile; for instance:
•	http://informant.dartmouth.edu/
•	http://www.northernlight.com/

Fee-based databases

As mentioned elsewhere in this text, a lot of information is available online, but only when a fee is paid to the producer and distributor. The first commercial computer systems that make information available online started around 1975. Most of them are now also available through the Internet. A famous, big company that offers all kinds of information, bibliographic as well as full texts is Dialog with a web site http://www.dialog.com/ that leads to several database access systems, including the original Dialog (located in the U.S.A.) and Data-Star (located in Europe). 
The amount of information offered by the biggest systems is huge, nowadays similar to the size of the whole WWW.

Online access information: future trends

An increasing amount of information becomes available online and a growing part of this is available free of charge. The quality of server and client software is increasing. As a consequence, an increasing number of end-users search for information online.

Dictionaries and encyclopaedias

Dictionaries and encyclopaedias are the first choice among many types of information sources, when we do not need detailed information on a common topic, or when we want to prepare a more detailed search on an unfamiliar topic, by searching for the right spelling, synonyms, context…
Many dictionaries and encyclopaedias are available through the WWW free of charge. Some examples of famous freely accessible encyclopaedias are
•	The Encyclopædia Britannica including Merriam Webster dictionary and links to selected WWW sites, available from http://www.britannica.com/
•	The Encarta Concise Free Encyclopedia at http://encarta.msn.com/
A list of encyclopaedia on the Internet is provided for instance at http://www.internetoracle.com/encyclop.htm
Other lists of encyclopaedia on Internet can be found as a part of Internet directories that are accessible free of charge.

Finding books

Even in this age of Internet-based information sources, a lot of information is still distributed in the form of printed books. The content of most books is (still) not available on the Internet. Most Internet search tools do NOT allow us to find out about the existence of books that may be interesting for us. So, specific search tools to find books can be useful. To find currently available books, the bibliographic databases assembled by big bookshops are interesting. Several offer a good coverage and are accessible free of charge. A few examples:
http://www.amazon.com/ and more local versions like http://www.amazon.co.uk/
http://www.bn.com/
http://www.blackwell.co.uk/
Even comparisons of the catalogues and offerings of shops of books (as well as of music, movies and many other goods) are available free of charge. See for instance http://www.dealtime.com/
Mainly to find older books, the catalogues of libraries can be useful. Most of the big important ones are accessible online and free of charge.

Finding journal articles

Thousands of fee-based online access databases offer bibliographies or full-texts of journal articles in particular subject domains. Only a few organisations offer large databases that allow us to access bibliographies of articles published in journals in all subject domains, free of charge. Furthermore, they can also deliver us the full text documents for some fee, not free of charge. Some examples: 
http://www.northernlight.com/
http://www.ingenta.com/
http://form.inist.fr/public/eng/conslt.htm

Electronic newsletters and journals

Since the end of the 1990s, electronic journals have become a new communication medium that cannot be neglected. We can distinguish various types: equivalents of a version printed on paper, and purely electronic publications. The WWW has become the most important platform for access to electronic newsletters and journals.

Citation searching

Besides the common searching for information by keywords related for instance to the subject of the topic, we can also exploit the citations, the references in scientific articles, to find related and perhaps relevant information. The leading information system that allows this approach is the Web of Science, produced by the Institute for Scientific Information.

Computer network interest groups

Computer-network-based interest groups are a means for information exchange between people with a common interest or concern. They enable their members to keep abreast of new developments, and to tap into the expertise of the community represented by the group. We can distinguish several systems, including those based on electronic mail and those based on Usenet News. Furthermore, since the 1990s, the WWW has become a gateway to these and a basis for similar systems. We can identify potentially relevant groups and the way to become a member, by searching the WWW, or more directly by free of charge browsing a directory or by searching a database describing such groups; see for instance http://www.liszt.com/ and http://groups.yahoo.com/. Furthermore, a partial archive of messages distributed through Usenet is also available free of charge at http://groups.google.com/.

Bibliography

Fristrup, J.A. (1994). Usenet netnews for everyone. Englewood Cliffs, New Jersey : PTR Prentice Hall. 1994. 396 pp. [One of the few books that is completely devoted to the group communication system Usenet news.]

Large A., Tedd L.A., and Hartley R.J. (1999). Information seeking in the online age: principles and practice. London : Bowker-Saur. 308 pp. [One of the best and most recently updated books about searching information online. It is general, not focusing on a particular subject domain.]

Lynch C. (1997). Searching the Internet. Scientific American, March 1997, 44-48. [A good overview of Internet search engines for non-experts.]

Gale directory of databases. Detroit : Gale Research Inc., 1994-... [The leading directory with descriptions of thousands of databases available on CD-ROM and/or online. It exists in a printed version updated two times per year and in an online accessible version.]

Notess G.R. Search engine showdown. [online] Available from: http://searchengineshowdown.com/ [cited February 2000] [This WWW site gives free access to an overview of general search tools to find information on the Internet. Regularly updated at least up to now.]

Schwartz C. (1998) Web search engines. Journal of the American Society of Information Science, Vol. 49, No. 11, 973-982. [A good scholarly review article about Web search engines.]

Searching the Internet: recommended sites and search techniques. [Online] Available from: http://www.albany.edu/library/internet/search.html [A freely accessible site on the WWW that offers a good introduction to finding information on the Internet.]