1 Finding information through Internet and the WWW in 2002 about pediatrics Paul Nieuwenhuysen Vrije Universiteit Brussel Informatie- en Bibliotheekwetenschap, Universitaire Instelling Antwerpen België Invited lecture for medical doctors (specialists pediatrics) Onze Lievevrouwziekenhuis, Mechelen, March 2002 These slides are available from

2 De slides en bibliografie van cursussen rond informatie Slides met hyperlinks zijn beschikbaar online via WWW bij het studiemateriaal bij de cursussen binnen: / Een bibliografie bij elk hoofdstuk is beschikbaar online via WWW:

3 Online access information sources and services Introduction

4 Discovering online access information sources Equipment and tools required: »A microcomputer »Data communication facilities »Tools to locate information sources »Some knowledge and skills »...

5 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.

6 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)

7 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.

8 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?

9 Internet based information sources: problems / difficulties (Part 3) Change is the only constant: Information sources are constantly changing, growing, but sometimes disappearing.

10 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.

11 Internet based information sources: problems / difficulties (Part 5) Slow: The Internet is in many places and for many applications not yet fast enough.

12 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.

13 Internet based information sources: how many? how much information? In 2001: More than million unique URLs in the total Internet More than 10 terabyte (= gigabyte) of text data

14 Increasing number of online public access databases Source: Gale Directory of Databases, 1997.

15 Online access information sources and services Types of online access information systems

16 Types of online access information 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.)

17 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”,...

18 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)...

19 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...

20 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)

21 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

22 Types of online access information sources by file format For instance: »TXT (ASCII) »DOC »HTM, HTML, SHTML,… »PDF »PCX »TIF, TIFF »GIF »JPG »PNG »AVI »MPG »ASF »…

23 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 )

24 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.)

25 WWW sites classified by language English: about 87% Other languages: 13% in 1999

26 Online access information sources and services Internet-based encyclopedias

27 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.

28 Encyclopedias accessible through Internet and WWW: examples Encarta Concise Free Encyclopedia » Encyclopædia Britannica only a small part is available free of charge + links to selected WWW sites » Encyclopædia Britannica Concise » Example

29 Encyclopedias accessible through Internet and WWW: examples The Canadian Encyclopedia (in English and in French): » Example

30 Encyclopedias accessible through Internet and WWW: overviews A list / overview of encyclopedia on the Internet: Other lists of encyclopedia on Internet can be found as a part of more general directories of Internet-based information sources. Example

31 Online access information sources and services Internet search functions built in browser software

32 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

33 The Internet search button of browsers: introduction Common graphical browsers provide a search function and a search button. Examples: Netscape, Microsoft Internet Explorer

34 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.

35 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.

36 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.

37 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.

38 Online access information sources and services Internet directories and indexes

39 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)

40 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)

41 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!

42 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.

43 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.

44 Internet global subject directories: Yahoo! A hypertext global subject directory can be found at and at many other sites, including Entries are NOT rated. Accessible free of charge. Example

45 Internet global subject directories: Yahoo! links in pediatrics Health > Medicine > Pediatrics: International Pediatric Chat - for professionals to share information and education regarding children's health care.International Pediatric Chat National Med/Peds Residents' Association - organization for residents, practioners and medical students interested in combined internal medicine and pediatrics.National Med/Peds Residents' Association Neonatology Network - information and communication platform for neonatologists and pediatricians.Neonatology Network Pediatria OnLine - qui si parla di bambini, fra pediatri e con le famiglie.Pediatria OnLine Pediatric Critical Care Pediatric Database (PEDBASE) - containing descriptions of over 500 childhood illnesses.Pediatric Database (PEDBASE) Pediatric Endocrinology Conference - LWPES/ESPE joint meeting occuring July Pediatric Endocrinology Conference Pediatric Endoscopic Photos - illustrating intestinal problems in children.Pediatric Endoscopic Photos Example

46 Internet global subject directories: Yahoo! for pediatrics Health > Medicine > Pediatrics: link to a digital library (health sciences) for young patients Example

47 Internet global subject directories: Yahoo! to pediatrics organisations Health > Medicine > Pediatrics > Organizations: link to the American Academy of Pediatrics Example

48 Internet global subject directories: Yahoo! links to pediatrics schools Health > Medicine > Pediatrics >Schools, Departments, and Programs University of Rochester - partnership between pediatric residents and community-based agencies that serve children and their families.University of Rochester Michigan State Royal College of Paediatrics and Child Health - responsible for training, examinations, professional standards, and organisation of child health services for the UK.Royal College of Paediatrics and Child Health Tohoku University University of Alabama at Biringham - programs and training opportunities in pediatrics. Also contains faculy information and sub-speciatlty descriptions.University of Alabama at Biringham … Example

49 Internet global subject directories: Yahoo! Example: link to an e-journal Health > Medicine > Pediatrics >Journals: link to an electronic journal Example

50 Internet global subject directories: Yahoo! Example: link to a directory Health > Medicine > Pediatrics >Web directories: link to a directory of sites on the WWW related to pediatrics Example

51 Internet global subject directories: Yahoo! Example: link to a directory Health > Medicine > Pediatrics >Web directories: link to a directory of sites on the WWW related to pediatrics Example

52 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.cape town Example

53 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. Example

54 Internet global subject directories: Britannica A hypertext global subject directory can be found at Entries are rated. Accessible free of charge. Combined and integrated with a great encyclopedia. Example

55 Internet global subject directories: BUBL A hypertext global subject directory to more than WWW sites for the higher education community can be found at Accessible free of charge. Example

56 Internet global subject directories: BUBL for pediatrics Example

57 Internet global subject directories: Google directory A hypertext global subject directory can be found at Accessible free of charge. Very similar to the Open Directory Project. Example

58 Internet global subject directories: Librarians' Index to the Internet A hypertext global subject directory can be found at Accessible free of charge. Example

59 Internet global subject directories: LookSmart A hypertext global subject directory can be found at Links are offered to LookSmart by the Internet index AltaVista. A search in the LookSmart index is also executed with the Internet index AltaVista. Accessible free of charge. Example

60 Internet global subject directories: Open Directory Project A hypertext global subject directory can be found at Accessible free of charge. Example

61 Internet global subject directories: Resource Discovery Network A collection of hypertext subject directories that focus on academic information sources can be found at Accessible free of charge. Example

62 Internet global subject directories: lists of directories Many Internet global subject directories exist, but the ideal one is not available. Overviews / lists of Internet subject directories exist also. Examples (accessible free of charge): » »

63 Internet subject directories: non-global, more specific systems a directory limited to sources in/of a country or region a directory restricted to a specific subject domain (“portal”) a global subject directory the complete WWW can lead to

64 Internet subject directories focusing on a specific subject domain (Part 1) Computer science & engineering: Social sciences: Marine science and oceanography: Examples

65 Internet subject directories focusing on a specific subject domain (Part 2) Medicine and healthcare: general: Medicine and healthcare: General pediatrics: Examples

66 Internet subject directories focusing on a specific subject domain (Part 3) Fishing: Art, architecture and the media: or Examples

67 Internet subject directories focusing on a specific subject domain: example A directory of sites on the WWW related to pediatrics Example

68 Internet subject directories focusing on a specific subject domain: example A directory of sites on the WWW related to pediatrics Example

69 Internet local subject directories: examples in Belgium The guide developed by the public libraries in Flanders: Examples

70 Internet indexes: automated search tools Several systems allow to search for and to locate many items (addressable resources) in the Internet in a more systematic, direct way than by only browsing/navigating. These systems do NOT search the contents of computers through the real Internet in real time and completely when a user makes a query. Searching in that way would be much too slow due to limitations in the technology.

71 Internet indexes: scheme of the mechanism User searching for Internet based information Internet client hardware and software user interface to a search engine Internet information source Internet index search engine Internet crawler and indexing system database of Internet files, including an index

72 Internet indexes: description of the mechanism 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 WWW form, to allow the user to search through that database

73 Internet indexes: AltaVista Example The primary search interface can be found in the US: (These addresses all lead to the same information.) Mirror site in UK:

74 Internet indexes: AltaVista: features Allows full text searching of the WWW Allows advanced Boolean searching (in “Advanced” mode) Offers relevance ranking of search results Offers a link to an Internet subject directory (Looksmart) Offers links to systems to find images, sounds,… (multimedia) in the Internet Example

75 Internet indexes: AltaVista simple versus advanced “Simple” is suited for instance for searches »with only 1 concept expressed as a series of synonyms, narrower terms,... such as a search for a person, a company, an institute,... »when ranking is important “Advanced” is suited for instance for searches »with more than 1 concept so that an AND combination is useful, besides an OR combination »when ranking is not important Example

76 Internet indexes: Fast = All the Web Example The search interface can be found at: You can search the WWW and ftp servers. The database is one of the biggest.

77 Internet indexes: Google (Part 1) You can search for WWW pages at Does NOT offer/allow »full Boolean searches; »stemming/truncation. Example

78 Internet indexes: Google (Part 2) For retrieval an algorithm is used that takes into account the links between WWW pages. A retrieved page is ranked higher when »many sites/pages point to it »“important” sites/pages point to it Searches include full text searching of files on the WWW; not only html pages, but also files in the formats Adobe PDF, Microsoft Word, Microsoft Excel,… Example

79 Internet indexes: Google additional features Besides a system to search for WWW pages, Google offers also »a subject directory »searching for images on the WWW »searching an archive of Usenet messages + posting to Usenet groups Thus Google has become a great integrator / aggregator. Example

80 Internet indexes: Hotbot The search interface can be found at You can search the WWW Based on an Internet index created by Inktomi. Allows advanced, Boolean searching. Example

81 Internet indexes: Lycos The search interface can be found at Has been based on various databases of WWW pages over time. In : based on the Fast database of WWW pages, that forms also the basis for the search system Alltheweb. Example

82 Internet indexes: MSN Web Search The search interface can be found with the search functions build into Microsoft Internet Explorer and at Offered free of charge by Microsoft. You can search for Web content. Since Is based on an Internet index created by another company. Example

83 Internet indexes: coverage / size of each index The indexes grow and their “size ranking” is variable. Biggest systems in 2002: AltaVista (Fast =) All the Web (serving also Lycos) Google Systems based on the INKTOMI database of WWW pages, such as Hotbot, MSN Web search,…

84 Internet indexes: delay in indexing new pages The great, well known, international Internet indexes have a delay of more than 1 month in indexing new pages. (according to Lawrence and Lee Giles, Nature, 1999, Vol. 400, pp ) So they are not suitable to search for rapidly changing recent information (such as “news”) (unless they index a small selection of important news sites more frequently)

85 the complete WWW a global Internet index an index limited to sources in/of a country or region Internet indexes: non-global, regional systems

86 Internet indexes for citation searching: introduction Some Internet indexes / search engines allow you to search for documents / pages / URLs that link to a particular page, to some URL that you already know (such as one of the web pages that you have developed or that you have made available yourself). Linking to a URL is similar to citing an information source. Such search systems can be used to analyse web citations. Web citations are sometimes named “sitations”.

87 Internet indexes for citation searching: examples of systems AltaVista but note that “Simple search” and “Advanced search” may give different results Google Hotbot Examples

88 Internet indexes for citation searching: query syntax For details about the required query syntax, query formulation, see the online manual or help pages of the search system that you want to use.

89 Internet indexes for citation searching: applications Citation searching on the WWW or on an intranet can be used »to get an idea of the importance, the fame, the impact of a particular web document, as measured by the number of links/citations to that page »to find out who has considered a particular page as interesting enough to make a link to »to find comments/criticisms on a particular web document

90 Multi-threaded Internet search systems: relations User an Internet meta-search system Internet search system 1 Internet search system database 1 WWW pages Internet search system 2 Internet search system database 2

91 Multi-threaded Internet search systems: server-based or client-based Online accessible on a server in the Internet. On the client, “meta-search software”.

92 Internet information sources Coverage of Internet directories and Internet indexes A global Internet index A global Internet directory

93 Global Internet search tools: a comparison Global Internet directories Only a limited selection of Internet sources Browsing information sources is easy Good for broad searches Global Internet indexes About 1/3 of the Internet is covered by an index Searching requires some skills and knowledge Good for specific, narrow searches Multi-threaded search systems These get information from directories and indexes Searching requires some skills and knowledge Good when even 1 index does not yield information

94 Internet indexes cover only a part of the Internet: introduction The “visible” part of Internet The “hidden, invisible” part of Internet and the WWW, (that is not searchable using a global index like, AltaVista, Google...)

95 Internet Internet indexes cover only a part of the Internet: scheme WWW Databases and file archives accessible through the Internet telnet ftp... telnet ftp... CGI, ASP,... Rapidly changing information, such as news Information accessible only when passwords are used Static indexable texts in the WWW ( = on HTTP server computers) covered partly by Internet indexes Word files PDF files

96 Database accessible over the Internet: a famous example: Medline/PubMed Example

97 Database accessible over the Internet: a famous example: Medline/PubMed Medline is a database of descriptions of articles in the area of medicine, published in more than scientific journals. This database is accessible through several different retrieval systems on the Internet and the WWW. Medline/PubMed is one of the systems that provide access to the database. Available from These systems are provided free of charge by the USA National Library of Medicine. Example

98 Internet indexes cover only a part of the Internet: conclusion for users When you want to retrieve information about a particular subject from the Internet, use not only WWW indexes, but use also other sources accessible through the Internet »anonymous ftp file archives, » based interest groups; Usenet newsgroups, »databases (book and journal bibliographies, library catalogues, archives of group messages, directories, atlases,…) »rapidly changing information, such as news »information accessible only when passwords are used

99 Gateways to Internet databases accessible free of charge Most Internet search engines search classical, static WWW pages and not databases accessible through the WWW. However, some systems offer a gateway to search databases on the Internet. Examples: (See also other more general directories/overviews/lists of Internet information sources.)

100 Example Gateways to Internet databases accessible free of charge: invisibleweb

101 Finding images on the Internet: introduction Several public access search systems are available free of charge to search for images / pictures (either artwork, either photos, or both) on the Internet. 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”).

102 Examples Finding images on the Internet: examples of search engines !!! ! !!!! or through !! (also audio and video, choose not the normal text search, but IMAGES in the user interface.) !

103 Examples Finding images on the Internet: screen shot of a Google image search

104 Guide to searching the Internet available through WWW Searching the Internet: recommended sites and search techniques. [Online] Available from: The RDN virtual training suite. [Online] Available from: offers training for users with a specific academic or professional interest.

105 Current awareness services focusing on WWW pages: introduction Tracking changes in one or more public access pages on the WWW or finding new pages, is possible »by using one of the available, suitable, programs loaded on your client workstation »through “alert” services based on a server on the WWW —that track updates for the user/subscriber —and send alerts by to the user/subscriber Few systems are free of charge.

106 Current awareness services focusing on WWW pages: Tracerlock can use one of several external Internet indexes with a simple search query given by you, to discover relevant changed or new WWW pages for you in the futurehttp:// Example

107 Online access information sources and services Public access book databases

108 Public access book databases: introduction Even in this age of Internet-based information sources, a lot of information is still distributed in the form of printed books. The contents of most books is (still) not available on the Internet. Most Internet search tools do NOT allow you to find out about the existence of books that may be interesting for you. So, specific search tools to find books can be useful.

109 Public access book databases: an overview (Databases by publishers.) Databases by book distributors / bookshops! Online public access library catalogues (Databases of computer-based versions of books.)

110 Public access book databases provided by bookshops 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.

111 Book databases accessible free of charge: examples (Part 1) Amazon.com (US): note: amazon, NOT amazone Barnes and Noble (US): Blackwell’s on the Internet (International, academic books): Examples

112 Book databases accessible free of charge: examples (Part 2) VLB for books in German For books in French Boeknet - De Nederlandse Internet Boekhandel (Dutch) Examples

113 Book databases accessible free of charge: examples (Part 3) Proxis (Belgium) Virtual Book Shop (good for old books) Examples

114 Free public access bibliographic book database + price comparisons Even comparisons of the catalogues of shops of books (as well as of music, movies and many other goods) are available free of charge. See for instance » »

115 Example of an international public access dissertation database The dissertation database of UMI is available from: A part is available free of charge. Examples

116 Database of links to the full text of many books A database (accessible free of charge ) of links to the full text of many books: Examples

117 Collection of links to public access book databases See for instance Internet directories like Yahoo! that lead to information about books. Examples

118 Current awareness service for books Some systems can alert the user that a new book has been published when this fits the interest profile of the user. Such an interest profile can be stored on the server of the system in the form of »keywords, or »subject categories / subject fields Example:

119 Online access information sources and services Library Online Public Access Catalogues = OPACs

120 Online Public Access Catalogues of libraries Mainly to find older books, the catalogues of libraries can be useful. Most are accessible online and free of charge.

121 Online Public Access Catalogues = OPACs: definition Online Public Access Catalogue: a term used to describe any type of computerized library catalog offered to the public by online login

122 Online access library catalogues: The Library of Congress, U.S.A. >15 million books + >10 million other documents In Washington DC, U.S.A. Accessible online via WWW Access free of charge Example

123 Online access information sources and services Fee-based online public access information services

124 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. The first commercial computer systems that make information available online were born around Most of them are now also available through the Internet.

125 Fee-based online access services: examples (Part 1) Location of the computer(s)U.S.A. U.S.A. U.S.A. U.S.A., Taiwan, UK Switzerland U.S.A. Name America On Line OCLC Ovid Technologies CompuServe Cambridge Data-Star Dialog EBSCO Examples

126 Fee-based online access services: examples (Part 2) Location of the computer(s) U.S.A. U.S.A. U.S.A., The Netherlands,... Germany - U.S.A. - Japan The Netherlands... Name Elsevier ScienceDirect Factiva ISI (Web of Science, JCR,…) LexisNexis MSN (Microsoft) Prodigy Silver Platter STN Swets (e-journals)... Examples

127 Online information services: various names for similar systems (fee-based) online (access) information service (fee-based) online (access) computer service databank database vendor host computer aggregator...

128 Online information services: total size of their databases In 1999: The big host systems and the public access WWW pages offer a comparable quantity of information: WWW offered about 8 terabytes (= gigabytes) of text data (according to Lawrence and Lee Giles, Nature, 1999, Vol. 400, pp ) Dialog offered about 9 terabytes (= gigabytes) (in 1998) »6 billion pages of text »3 million images

129 Databases of online public access databases Example »Gale directory of databases ! Their coverage: »online access databases »(databases accessible on CD-ROM) »...

130 Databases of databases: Gale Produced in U.S.A. Not free of charge Available in various formats: »printed »on CD-ROM »online via the host systems Data-Star, Dialog, with a payment required for each use »online through the Internet through various hosts, for a fixed price per year to be paid in advance

131 Online access information sources and services Online access databases about journal articles

132 Online access databases about journal articles: overview Thousands of fee-based online access databases offer bibliographies or full-texts of journal articles in particular subject domains. Only few large databases offer access to bibliographies of articles published in journals, free of charge.

133 Online access databases about journal articles: Northern Light Northern Light allows searching for the full text of articles from many journals/magazines. Searching is free of charge. Available from » » Payment is required to receive the full text of an article. Example

134 Online access databases about journal articles: Ingenta (1) Ingenta Journals allows you to search a bibliographic database of millions of journal articles, including titles, authors, in many cases abstracts. Searching is free of charge. Example

135 Online access databases about journal articles: Ingenta (2) Payment is required to receive the full text of an article. Ingenta has acquired Uncover in Available from » » Example

136 Online access databases about journal articles: allows you to search in a bibliographic database, NOT full-text (Journal articles, Journal issues, Books, Reports or Conferences, doctoral dissertations) at the Institut de l'Information Scientifique et Technique, France. Searching is free of charge. Available from Payment is required to receive the full text of an article. Example

137 Online access databases about journal articles: Infotrieve Infotrieve allows you to search free of charge in a bibliographic database of the articles of more than journal titles and conference proceedings, NOT full-text. Current awareness services are also offered free of charge. Available from Payment is required to receive the full text of a document. Example

138 Online access databases about journal articles: Medline Medline produced by the National Library of Medicine (USA) allows searching a bibliographic database of articles in the field of medicine. free of charge available from many sites, including »PubMed of the National Library of Medicine (USA) and »Ingenta Example

139 Online access databases about journal articles: Medline through PubMed Example

140 Online access databases about journal articles: Web of Science The Web of Science offers access through the WWW to a database of bibliographic descriptions of scientific journal articles in all subject domains. This database is (only) available to members of organisations/institutes/companies/consortia that pay a yearly fee to the producer/publisher of the database. This database is not only suitable for subject searching, but also for citation searching.

141 Online access information sources and services Electronic newsletters and journals

142 Electronic newsletters and journals: introduction Since the end of the 1990s, electronic journals have become a new communication medium that cannot be neglected. Author / Sender Editor Reader / Receiver

143 Electronic newsletters and journals: variations on a theme We can distinguish several methods »of distribution and access »of formatting the information (PDF, HTML,…) »of pricing and licensing »of restricting access (authentication and authorization of legitimate users) »to integrate access to e-journals with access to other information sources

144 Electronic newsletters and journals: various types and the price of access We can distinguish various types: »equivalents of a version printed on paper —Published almost simultaneously —Print version published long time before electronic version = long delay for the electronic version »purely electronic publications Price of access: from free of charge to very expensive

145 Electronic newsletters and journals: access and distribution methods Many different methods are used: »anonymous ftp »gopher »WAIS »electronic mail, listserv,... »Usenet News »loaded on local systems in universities or institutes »http, WWW !

146 Electronic newsletters and journals through the WWW The WWW has become the most important platform for access to electronic newsletters and journals.

147 Electronic newsletters and journals: example Example

148 Electronic newsletters and journals: example Example

149 Specialised directories of online access electronic journals Several directories / catalogs / overviews / databases / lists are available of electronic, computer-based, online accessible newsletters, newspapers, journals,... in particular subject domains. For example: a directory of journals in medicine accessible free of charge:

150 Online access information sources and services Computer-based information sources: criteria to evaluate their quality

151 Computer-based information sources: evaluation criteria (Part 1) Besides more general criteria applicable to all information sources, for those sources that are based on computers and networks we see the following criteria: Easy to navigate? »User-friendly information system? »Easy for users to orientate themselves within the resource and to find their way around it? »Is the resource organised into manageable chunks of information that can be browsed easily?

152 Computer-based information sources: evaluation criteria (Part 2) »Is a contents page or index offered that describes what is contained within the site? »Are there good navigational links within the pages (e.g. 'back', 'forward', 'home') »Are the links clearly labeled? »Is the navigation process supported by images? »Is there a single downloadable file for documents that exist as a series of separate pages? »Is there a search facility within the resource?

153 Computer-based information sources: evaluation criteria (Part 3) Good user support? »Good support that is offered to users to help them answer queries and problems that arise whilst using the resource? »Good computer-based, contextual help, documentation, training materials or tutorials? » contact(s) and telephone number(s) available?

154 Computer-based information sources: evaluation criteria (Part 4) Based on appropriate technologies? »Are technologies and standards used that will enable users to access and utilize all aspects of the resource? »Does the resource avoid that proprietary software should be used? »Does the resource avoid the use of proprietary extensions to HTML, which some browsers will not be able to recognize?

155 Computer-based information sources: evaluation criteria (Part 5) »Does the format allow access to the resource for all users, even for instance sight impaired and those who can only navigate by using the keyboard? Information integrity / High stability of the contents / Low volatility of the contents? »Is there adequate maintenance of the information content?

156 Computer-based information sources: evaluation criteria (Part 6) System integrity? »Site integrity relates to the stability of the site over time. This usually relates to the work of the site manager or web master. »Realise that individual sites can be moved or withdrawn at any time by those responsible for publishing information on the Internet, and that addresses, file structures, formats and interfaces can be altered without warning. »Is the site current and up to date?

157 Computer-based information sources: evaluation criteria (Part 7) »Is the site proven to be or expected to be durable in nature? »Is the site adequately administered and maintained?

158 Computer-based information sources: The Internet Detective 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:

159 Online access information sources and services Future trends

160 Online access information: future trends An increasing amount of information becomes available online. A growing amount of this online information becomes available free of charge. The quality of server and client software is growing.  A consequence is: An increasing number of end-users searching for information online.

161 Online access information: conclusion In the case of simple information needs, the WWW and the search tools can work like “magic”. However, in the case of more complicated information needs, there is still is no “magic button” that brings you immediately to all the required information.

162 Thank you The slides are available through the WWW from Any questions?