Online access information sources and services Introduction
Online information sources: summary • The following gives a general overview of online accessible information sources. • This overview is not limited to or focusing on a particular concrete subject domain/area.
Online information sources: prerequisites Before using online accessible information sources, you should ideally have some knowledge and skills related to • computer hardware • computer software • the Internet • the WWW • the concept of ‘information’ • information retrieval in general • the information market
Discovering online access information sources Equipment and tools required: • A microcomputer • Data communication facilities • Tools to locate information sources • Some knowledge and skills • ...
Growing importance of computer network information resources • Networked information resources are growing at a high rate, not only in volume but also in importance. There are many sources there which are vital to research and many others which 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 don’t, they are likely to be left behind, because most of their colleagues in institutions around the world will be doing just that.
Online access to information: avoid network traffic jams To access from Europe online information sources in the US, work when lines are not saturated.(better in the morning than in the afternoon)
Internet based information sources: problems / difficulties (Part 1) • Redundancy and overlap:On the one hand, there is too much information on some topics; in other words, the redundancy and overlap are high in many cases.Too few information sources: On the other hand, there are too few information sources on some topics.
Internet based information sources: problems / difficulties (Part 2) • No order is imposed on most sources.Quality checks / quality controls are not performed.Related to this: it is not required to register new information offered.Is the information that you find real, honest, authentic?
Internet based information sources: problems / difficulties (Part 3) • Change is the only constant: Information sources are constantly changing, growing, but sometimes disappearing.
Internet based information sources: problems / difficulties (Part 4) • Scattering: There is no single simple but powerful system to find relevant information through the Internet.In other words: integration / aggregation is still far from perfect.
Internet based information sources: problems / difficulties (Part 5) • Slow: The Internet is in many places and for many applications not yet fast enough.
Internet based information sources: problems / difficulties (Part 6) • In conclusion: Surfing, using the Internet, the WWW, can be a time sink instead of a productive activity.
Internet based information sources: how many? how much information? In 2001: • More than 1 000 million unique URLs in the total Internet • More than 10 terabyte (= 10 000 gigabyte) of text data
Increasing number of online public access databases Source: Gale Directory of Databases, 1997.
Online access information sources and services Types of online access information systems
Types of online accessinformation systems We can categorize the various online accessible information systems in various ways: • primary or secondary • based on information contents that is offered • online access method required (= communication protocol) • freely accessible versus accessible for a fee • computer file format (Of course these categorizations are normally not independent but related.)
Primary versus secondary computer sources / systems / services • Primary sources /systems /services directly useful • Secondary sources /systems /services • helping to access / use the primary services • “travel agencies”, “navigation services”, ...
!? Question !? Task !? Problem !? Do you know examples of primary and of secondary online information systems?
Types of online access information systems by contents • Documents (with or without hyperlinks) • Catalogues of editors and bookshops • Online public access library catalogues (OPACs) • Community/Campus-Wide Information Systems (CWIS) • Online access databases about journal articles • Electronic newsletters and journals • Computer file archives (documents, programs) • Interest groups (for instance Usenet Newsgroups) • ...
Types of online access information systems by access method • Remote login information systems and bulletin board systems (BBS) (telnet in the Internet) • Anonymous ftp servers, in the Internet • Usenet News servers (nntp in the Internet) • Gopher servers, in the Internet • Wide Area Information Servers (WAIS), in the Internet • World Wide Web servers = http servers (WWW), in the Internet • ...
Types of online access information systems: “free” versus “fee” • 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.
Types of online access information systems: “free” versus “fee” Public access information sources free of charge Fee-based online information services(NOT free of charge)
Types of online access information systems: “free” for members only Public access information sources free of charge Fee-based online information services(NOT free of charge) Fee-based online information services, made accessible “free of charge” by an institute to its members
For instance: TXT (ASCII) DOC HTM, HTML, SHTML,… PDF PCX TIF, TIFF GIF JPG PNG AVI MPG ASF … Types of online access information sources by file format
WWW sites classified by contents • Commercial: about 80% • Other 20%: • Science and education • Personal • others in 1999 (according to Lawrence and Lee Giles, Nature, 1999, Vol. 400, pp. 107-109.)
Commercial information provided through the Internet • Most of the information that is freely available on the WWW is provided by commercially oriented organisations. • Thus that information is not objective or scientific in most cases, but subjective or perhaps even misleading, and certainly 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 more objective information of high quality, as this is their way to survive commercially.)
WWW sites classified by language • English: about 87% • Other languages: 13% in 1999
Online access information sources and services Internet-based encyclopedias
Encyclopedias accessible through Internet and WWW • Dictionaries and encyclopedias are the first choice among many types of information sources, • when we do not need detailed information on a common topic • when we want to prepare a more detailed search on an unfamiliar topic, by searching for the right spelling, synonyms, context,… • Some dictionaries and encyclopedias are available through the WWW free of charge.
Example Encyclopedias accessible through Internet and WWW: examples • Encarta Concise Free Encyclopedia • http://encarta.msn.com/ • Encyclopædia Britannicaonly a small part is available free of charge + links to selected WWW sites • http://www.britannica.com/ • Encyclopædia Britannica Concise • http://education.yahoo.com/reference/encyclopedia/
Example Encyclopedias accessible through Internet and WWW: examples • The Canadian Encyclopedia(in English and in French): • http://thecanadianencyclopedia.com/
Example Encyclopedias accessible through Internet and WWW: overviews • A list / overview of encyclopedia on the Internet:http://www.internetoracle.com/encyclop.htm • Other lists of encyclopedia on Internet can be found as a part of more general directories of Internet-based information sources.
Online access information sources and services Internet search functions built in browser software
The Internet search functions built into browsers • Some Internet search functions are built into common leading browsers like • Microsoft Internet Explorer • Netscape • When connected to the Internet, you can use • The functions behind the “Search button” • Searching through the “Address” form
The Internet search button of browsers: introduction Common graphical browsers provide a search function and a search button. Examples: Netscape, Microsoft Internet Explorer
The Internet search button of browsers: comments (Part 1) • Such a search function offers in fact no searching, but (only) a link to a WWW site, often in the USA, which offers links or gateways to search tools on other servers. • It is faster in many cases to contact search tools directly.
The Internet search button of browsers: comments (Part 2) • The gateways may offer only a limited view on the properties of the real search tool used. • Such a search function can confuse users who may think that the searching capability is built more or less into the browser software, while searching relies on external servers.
Searching with browsers using the address form: introduction • A search for particular Internet documents can be performed by typing in keywords in the address form, when you are connected to the Internet,for instance with • Microsoft Internet Explorer • Netscape • This is based on transmitting the keywords to some Internet index through the Internet.
!? Question !? Task !? Problem !? Get some experience in using the address form of your web browser program to search for documents on a particular subject that are available on the WWW.
Searching with browsers using the address form: comments + An advantage is the ease of use. - A disadvantage is that it less clear what really happens, than when you access a well chosen and well known Internet directory or Internet index directly.
Online access information sources and services Internet directories and indexes
Internet: meta-information about Internet information sources • in printed manuals and guides: - it is not always possible to get a copy fast - it costs money to get a copy - they are soon out of date • offered on the WWW!: + directly available when we want to use the Internet + many systems are accessible free of charge + most systems are regularly updated • (“intelligent agent” software on client PC)
Internet: subject-oriented meta-information offered via WWW Information about information sources: in the form of • subject guides = texts with references • subject hypertext directories = subject guides • key word indexes, generated automatically, for searching • collections of links or forms to the above • (multi-threaded search systems)
Internet global subject directories:introduction • They are virtual libraries with open shelves, for browsing. • They are manually generated, man-made by many people. • They can be browsed following a tree structure or a more complicated variation. • The most famous of these systems belong to the most popular and most visited sites on the WWW: e.g. Yahoo!
Internet global subject directories: structure The structure corresponds to a classification that is in most cases specific for the particular overview. In other words: the well-known and classical universal classification systems are not used in most Internet directories.
Internet global subject directories: limitations • They cover only a small number of selected WWW sites, in comparison with the total number of sites that are accessible. • They are suitable mainly for broad searches that can be difficult to formulate in words, but NOT for more specific searches that require combinations of several concepts.
Internet global subject directories:searching directories with a query • Many of the Internet directories include an index to search their contents with a query. • 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.
Example Internet global subject directories: Yahoo! • A hypertext global subject directory can be found athttp://www.yahoo.com/ and at many other sites, includinghttp://www.yahoo.co.uk/ • Entries are NOT rated. • Accessible free of charge.
Example Internet global subject directories: searching with a query in Yahoo! (1) • The directory of Yahoo! can not only be browsed, but can also be searched with a query. • However, in this way the hierarchical structure is not well exploited. • For the formulation of a search query, Yahoo! can provide automatic assistance related to spelling and word variations. For instance: After searching for “Capetown”, Yahoo! Answers: Other Spellings: Try searching for cape town instead.
Example Internet global subject directories: searching with a query in Yahoo! (2) • 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.