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ISO/TC 46/SC 9 Home Page Excerpts from ISO 690-2
Information and documentation -- Bibliographic references -- Part 2: Electronic documents or parts thereof
IntroductionAn increasing number of publications and other documents are appearing in electronic form and are created, maintained, and disseminated on a computer system. An electronic document may be fixed and unchangeable, or it may take advantage of its computer environment to allow modifications in both form and content. An electronic document may or may not have a paper or other form of equivalent. In spite of the complexity of these documents, scholars, researchers, and others need to create references to these electronic resources in order to document their research. This part of ISO 690 provides guidance on the creation of those bibliographic references. Although an electronic document may stylistically resemble a print publication (such as a monograph, a serial, or an article or chapter), the physical characteristics inherent in printed publications may not appear in the electronic form. For instance, the existence of volumes, issues, and pages is essential to print formats, but not to electronic ones. A growing amount of scholarly communication through large telecommunications networks seems to fall somewhere between published articles and personal correspondence. Features that allow a user to move at will from one point in an electronic document to another point, or even to another document, add a complication not found in the traditional linear nature of print formats. Although a correspondence may be made between some print publications and some electronic documents, electronic documents have their own identity as computer programs, databases, files, or records which exist in a machine-readable format, such as online, on CD-ROM, on magnetic tape, on disk, or on another electronic storage medium. Bibliographic references to these electronic documents must reflect that identity, not one of paper surrogates. New formats and technologies for electronic documents will continue to develop. As such developments evolve into widespread international usage, this part of ISO 690 will be amended, where necessary, to accommodate new forms and features of electronic documents. 1 ScopeThis part of ISO 690 specifies the elements to be included in bibliographic references to electronic documents. It sets out a prescribed order for the elements of the reference and establishes conventions for the transcription and presentation of information derived from the source electronic document. This part of ISO 690 is intended for use by authors and editors in the compilation of references to electronic documents for inclusion in a bibliography, and in the formulation of citations within the text corresponding to the entries in that bibliography. It does not apply to full bibliographic descriptions as required by librarians, descriptive and analytic bibliographers, indexers, etc. ... some text omitted here .... 4 Sources of informationThe principal source of data contained in a reference is the item itself. The elements of the reference come from the electronic document itself or from accompanying documentation; in no case shall the reference require information that is not available from the source consulted. The data recorded in the reference shall refer to the specific copy of the document that was seen or used. For example, the data in a bibliographic reference to a document on the Internet shall reflect the title, dates, location information, etc. for the particular version that was seen and the particular network location from which that version was accessed. The preferred source of data within the item is the screen that displays the title or its equivalent (e.g., the initial screen display that follows sign-on or that carries the copyright notice). If the electronic document lacks such a screen, the necessary data may be taken from an alternative source, such as accompanying documentation or the container. 5 Outline of bibliographic referencesThe outlines that follow are designed to identify the constituent elements of bibliographic references to electronic documents and to establish a standard order or sequence for the presentation of those elements. The outlines cover references to databases, computer programs, electronic monographs, serials, bulletin boards and other electronic message systems, and parts of or contributions thereto. The same general framework applies to all these documents but those that have characteristics which are peculiar to their form of publication are dealt with in separate sections. Required and optional bibliographic elements are indicated as such in parentheses following the name of the element. Elements are required only if they are applicable to the item being cited and the information is readily available from the document itself or its accompanying material. It is recommended that elements listed as optional should also be included in the reference if the information is readily available. Specifications relating to each of the elements listed in these outlines are given in clause 7. 5.1 Electronic monographs, databases and computer programs5.1.1 Entire documentElement:
Primary responsibility (Required) SELECTED EXAMPLES (see print version for additional examples)
5.1.2 Parts of electronic monographs, databases or computer programsIn general, parts are dependent portions of a document which require the context supplied by the host document. If the item being referenced can be treated as an independent unit without loss of meaning, it should be referenced as a contribution (see clause 5.1.3). Element:
Primary responsibility (of host document) (Required) SELECTED EXAMPLES (see print version for additional examples)
5.1.3 Contributions to electronic monographs, databases or computer programsElement:
Primary responsibility (of contribution) (Required) SELECTED EXAMPLES (see print version for additional examples)
5.2 Electronic serials5.2.1 Entire serialElement:
Title (Required) EXAMPLES
5.2.2 Articles and other contributionsElement:
Primary responsibility (of contribution) (Required) EXAMPLES
5.3 Electronic bulletin boards, discussion lists and electronic messages5.3.1 Entire message systemElement:
Title (Required) SELECTED EXAMPLES (see print version for additional examples)
7.3 Type of medium
The type of electronic medium shall be given in square brackets after the title. The following words or their equivalent should be used: If desired, the type of publication (e.g. monograph, serial, database, computer program) may also be specified in the type of medium designator.
EXAMPLES: ... some text omitted here .... 7.6 Issue designation for serials7.6.1 PresentationFor electronic serials the issue designation shall be as complete as possible. It shall include the chronological designation (month, year, etc.) and numbering (volume number, issue number, etc.) given in the source. 7.6.2 Designation of the first issue onlyIf the reference is to the whole of an electronic serial that has not ceased, the chronological designation and/or numbering of the first issue only shall be recorded, followed by a hyphen and one space, e.g. "January 1995- , vol. 1, no. 1- ." If the beginning date is not found on the opening screen(s) of the electronic serial or in the accompanying documentation, the date of the earliest entry in the serial should be used, if known. 7.6.3 Designation of a complete or partial runIn a reference identifying either a complete or partial run of an electronic serial, the chronological designation and/or numbering of the first and last issues shall be recorded. If the beginning and ending dates are not found on the opening screen(s) of the electronic serial or in the accompanying documentation, the dates of the earliest and latest entries in the serial should be used, if known. ... some text omitted here .... 7.7.3 Place of publication unknownIf no place of publication is found on the electronic document or on accompanying material but it can be reasonably inferred, the place name shall be given in square brackets. If no place of publication can be ascertained, a phrase such as "place of publication unknown", "sine loco" or an equivalent abbreviation (e.g. "s.l.") should be recorded in lieu of a place name. For online documents that are accessed by means of a computer network, the place of publication element may be omitted if it can not be determined from other information in the source. In these cases, however, the network location of the document shall be given (see clause 7.12.1). ... some text omitted here .... 7.8.3 Publisher unknownIf no publisher's name is given in the source, a phrase such as "publisher unknown" or an equivalent abbreviation (e.g. "s.n.") should be recorded in lieu of a name. For online documents that are made available by means of a computer network, the publisher element may be omitted if it can not be determined from other information in the source. In these cases, however, the network address from which the specific document was accessed shall be given (see clause 7.12.1). 7.9 Dates7.9.1 PresentationIf it is deemed necessary because of the frequency of updates or revisions to an electronic document, the dates of publication, update, revision or citation may include the day, month, year, and time of day (e.g. 18 February 1997; 14:04:28 EST). Years shall be transcribed in arabic numerals. Dates that are transcribed completely in numeric form shall be in accordance with ISO 8601 (e.g. 1997-01-20). 7.9.2 Electronic documents spanning more than one dateIf an electronic document spans more than one date and is complete, such as a database to which no records are being added or an online serial that is no longer being published, the beginning and ending dates should be given (e.g. "September 1975-August 1984"). If the beginning and ending dates are not found on the opening screen(s) of the document or in its documentation, the dates of the earliest and latest entries in the document should be used, if known. If an electronic document spans more than one year and is not yet complete, such as a database that is still being updated or an active serial, the beginning date of the document shall be given followed by a hyphen and one space, e.g. "June 1991- ". If the beginning date is not found on the opening screen(s) of the document or in its documentation, the date of the earliest entry in the document should be used, if known. 7.9.2.2 Date of publication unknownIf the date of publication cannot be determined from the source, the date of copyright shall be recorded in its place. If no date of copyright is available and there are no other reliable indications of the date of publication for the electronic document, the phrase "date unknown" or its equivalent shall be recorded in lieu of a date. Optionally, for online documents that span more than one date (e.g. an entire database, electronic bulletin board or other electronic message system), the date of publication element may be omitted if it can not be determined from the source. In such cases, a date of citation shall be supplied in square brackets (see 7.9.4). 7.9.3 Date of Update/RevisionElectronic documents may be frequently updated or revised between editions or versions. Even when a document is closed to the addition of new records, it may still be updated for error correction or other maintenance. Where applicable, the date of the update or revision being cited shall be given after the date of publication using the terms given in the source (e.g. "updated January 1997" or "rev. 1 March 1997"). 7.9.4 Date of citationThe date on which the electronic document was actually seen shall be given in square brackets for documents which may be subject to changes (e.g. online documents) or when no other reliable date can be found in the source or the documentation. The date of citation shall be preceded by the word "cited" or an equivalent term.
EXAMPLES ... some text omitted here .... 7.11 Notes7.11.1 Physical descriptionInformation that describes the format of the document or the number and type of physical pieces associated with the electronic document should be given as a note. EXAMPLES
7.11.2 Accompanying materialInformation about any items accompanying the electronic document, such as user manuals or audiocassettes, may be recorded in a note. This information shall be preceded by the words "Accompanied by" or an equivalent phrase. 7.11.3 System requirementsInformation concerning system requirements should be recorded in a note. System requirements include the specific make and model of computer on which the document is designed to run; the amount of memory required; the name of the operating system and its version; the software requirements; and the kind and characteristics of any required or recommended peripherals. The wording supplied by the electronic document or its documentation should be used. To reduce ambiguity, it is suggested that the words "System requirements:" or an equivalent phrase precede this information. EXAMPLE System requirements: IBM PC or compatible; MPC Standard CD-ROM drive; DOS 3.30 or higher; 490 kB RAM; MS-DOS Extensions 2.1 or higher. 7.11.4 Frequency of publicationIf an electronic document, such as a database, is still being updated, the frequency with which it is updated should be given in a note, e.g. "Updated weekly"; "Reloaded annually"; "Continually updated"; "Quarterly". ... some text omitted here .... 7.12 Availability and access7.12.1 Online documentsInformation for identifying and locating the source of the document cited shall be provided for online documents. This information should be identified by the words "Available from" or an equivalent phrase. The location information for online documents within a computer network such as the Internet shall refer to the copy of the document that was actually seen and should include the method of access to the document (e.g. FTP) as well as the network address for its location. The elements of location information (e.g. address of the host computer, directory name, file name) shall be transcribed with the same punctuation, upper case and lower case letters as given in the source. EXAMPLES
7.12.2 Other availability informationInformation on any other locations or forms of the document may also be given. This information should be clearly separated from information that refers to the location of the actual document cited and should be preceded by the words "Also available" or an appropriate equivalent phrase. EXAMPLE Also available in HTML version from: <http://info.lib.uh.edu/pacsrev.html>. 7.13 Standard numberThe standard number, if any, assigned to the item being cited shall be recorded. The standard number shall be introduced by the appropriate identifier for the standard numbering system used (e.g. ISSN; ISBN).
EXAMPLES 7.14.1 Parts of electronic documentsIn a reference to a part of an electronic document, which is not a separate contribution, the details unique to the part (e.g. chapter or part designation and title) and its numeration and location within the host document shall be placed after the bibliographic data for the work as a whole and preceding the notes, statement of availability and standard number, if applicable. 7.14.2 Contributions in electronic documentsIn a reference to a separate contribution in an electronic document, the details relating to the contribution (e.g. its author and title) shall precede the details referring to the host document as a whole, and shall be clearly distinguished from it by typography, punctuation or a word such as "In". The numeration and location of the contribution within the host document shall be placed after the bibliographic data for the host and preceding the notes, statement of availability and standard number, if applicable. 7.14.3 Numeration within host document or systemThe record number or other numbers assigned to a part or contribution as its identifier within the host document or system should be recorded when such numeration will remain constant each time the part or contribution is retrieved from the host. This number should be preceded by a descriptive phrase, such as "Record no.", "Item no.", "Accession no.", or an equivalent phrase appropriate to the document. 7.14.4 Location within host documentThe location of the part or contribution within the host document shall be given if the format of the document includes pagination or an equivalent internal referencing system. This specification of location should be designated in this order of preference:
1) page, screen, paragraph, or line number when these features are fixed features of the part or contribution or of the database (e.g. "pp. 5-21"; "lines 100-150)"; If the document does not include pagination or an equivalent internal referencing system, the extent of the item may be indicated in square brackets in terms such as the total number of lines, screens, etc. (e.g. "[35 lines]" or "[approx. 12 screens]"). ... some text omitted here .... |
Journal impact factor: a brief review Eugene Garfield, PhD CMAJ 1999;161:979-80 See also:
I first mentioned the idea of an impact factor in 1955. At that time it did not occur to me that it would one day become the subject of widespread controversy. Like nuclear energy, the impact factor has become a mixed blessing. I expected that it would be used constructively while recognizing that in the wrong hands it might be abused. In the early 1960s Irving H. Sher and I created the journal impact factor to help select journals for the Science Citation Index (SCI). We knew that a core group of highly cited large journals needed to be covered in the SCI. However, we also recognized that small but important review journals would not be selected if we depended solely on simple publication or citation counts. We needed a simple method for comparing journals regardless of their size, and so we created the journal impact factor. The use of the term "impact factor" has gradually evolved, especially in Europe, to include both journal and author impact. This ambiguity often causes problems. It is one thing to use impact factors to compare journals and quite another to use them to compare authors. Journal impact factors generally involve relatively large populations of articles and citations. Individual authors, on average, produce much smaller numbers of articles. A journal's impact factor is based on 2 elements: the numerator, which is the number of citations in the current year to any items published in a journal in the previous 2 years, and the denominator, which is the number of substantive articles (source items) published in the same 2 years. The impact factor could just as easily be based on the previous year's articles alone, which would give an even greater weight to rapidly changing fields. A less current impact factor could take into account longer periods. Alternatively, one could go beyond 2 years for the source items in the denominator, but then the measure would be less current. All citation studies should be normalized to take into account variables such as field, or discipline, and citation practices. Citation density and half-life are also important variables. The citation density (mean number of references cited per article) would be significantly lower for a mathematics article than for a life sciences article. The half-life (number of years, going back from the current year, that cover 50% of the citations in the current year to the journal) of a physiology journal would be longer than that of a journal of molecular biology or astronomy. The impact factors currently reported by the Institute for Scientific Information in Journal Citation Reports (JCR) may not provide a complete enough picture for slower changing fields with longer half-lives. Nevertheless, when journals are studied within disciplinary categories, the rankings based on 1-, 7- or 15-year impact factors do not differ significantly, as was recently reported in The Scientist. In the first report the top 100 journals with the highest impact factors were compared; in the second report the next 100 journals were compared. When journals were studied across fields, the ranking for physiology journals as a group improved significantly as the number of years increased, but the rankings within the group did not. Hansen and Henrikson reported "good agreement between the journal impact factor and the overall [cumulative] citation frequency of papers on clinical physiology and nuclear medicine." The impact factor calculations used by JCR tacitly imply that all editorial items in Science, Nature, the Journal of the American Medical Association, CMAJ, the British Medical Journal and The Lancet can be neatly categorized. Such journals publish large numbers of items that are neither traditional research nor review articles. These items (e.g., letters, news stories and editorials) are not included in JCR's calculation of impact, yet we all know that they may be cited. Indeed, the JCR numerator includes citations to any item published in these journals. The assignment of codes by article type is based on human judgement. A news story might be perceived as a substantive article, and a research letter might not be. Furthermore, no effort is made to differentiate clinical versus laboratory studies or, for that matter, practice-based versus research material. There is a widespread but mistaken belief that the size of the scientific community that a journal serves affects the journal's impact. This assumption overlooks the fact that the larger the author and article pool for citing, the larger the number of published articles to share those citations. Many articles in large fields are not well cited, whereas those in small fields may have unusual impact. Therefore, the key determinants in impact are not the number of authors or articles in the field but, rather, the mean number of citations per article (density) and the half-life or immediacy of citations to a given journal. This distinction was discussed many years ago in an essay on "Garfield's constant". The size of a field, however, will determine the number of "super-cited" papers. While a few famous methodology papers achieve a high threshold of citation, thousands of other methodology papers do not achieve this distinction. The time required to review manuscripts may also affect impact. If reviewing and publication are delayed, references to articles that are no longer current may not be included in the impact calculation. Even the appearance of articles on the same subject in the same issue of a journal may have an effect. Opthof recently showed how journal impact performance varies from issue to issue. For greater precision, it is preferable to conduct item-by-item journal audits so that any differences in impact for these different types of editorial items can be taken into account. For a small number of journals a bias may be introduced by including in the numerator these extra citations to items that are not part of the denominator of source articles. Clearly, if the denominator is smaller than the actual number of published items, it will increase the journal's impact factor. This in turn may alter the rankings. However, most journals publish primarily substantive research or review articles. Therefore, statistical discrepancies are significant only in rare cases. The JCR data have come under some criticism for this reason among others. Most discrepancies are eliminated altogether in another database called the ISI Journal Performance Indicators (JPI) (www.isinet.com/products/rsg/jperfind.html). This annual compilation now covers citations from 1981 to 1998. Because the database links each source item to its citation in JPI, the impact calculations are more precise, in that citations are counted only for substantive items and it is possible to obtain impact measures covering longer periods. For example, the cumulated impact for CMAJ articles published in 1981 is 9.04 (derived by dividing the number of articles published in CMAJ that year [224] into the number of citations between 1981 and 1998 [2024]). Using similar data, I was able to calculate 7- and 15-year impact factors for the 200 high-impact scientific and medical journals mentioned earlier. In addition to helping libraries decide which journals to purchase, journal impact factors are also used by authors to decide where to submit their articles. As a general rule, the journals with high impact factors are among the most prestigious today. The perception of prestige is a murky subject. Some would equate prestige with high impact. However, some librarians argue that the numerator in the impact-factor calculation is in itself even more relevant. Bensman stated that this 2-year citation count is a better guide to journal significance and cost-effectiveness than is the impact factor. Journal impact can also be useful in comparing expected and actual citation frequency. Thus, when ISI prepares a personal citation report it provides data on the expected citation impact not only for a particular journal but also for a particular year, because impacts change from year to year. For historical comparisons, a 1955 article cited 250 times might be considered a "citation classic," whereas the threshold for a 1975 article might be 400 and a 1995 article 1000. The use of journal impact factors instead of actual article citation counts is probably the most controversial issue. Granting and other policy agencies often wish to bypass the work involved in obtaining actual citation counts for individual articles and authors. Recently published articles may not have had enough time to be cited, so it is tempting to use the impact factor as a surrogate, virtual count. Presumably the journal's impact and the mere acceptance of the paper for publication is an implied indicator of prestige and subsequent citation. Typically, when the author's bibliography is examined, a journal's impact factor is substituted for the actual citation count. Thus, use of the impact factor to weight the influence of a paper amounts to a prediction, albeit coloured by probabilities. The assumption that any recent article cannot be evaluated may be wrong. Indeed, papers that achieve rapid impact are cited within months and certainly within a few years. This pattern of immediacy has enabled the ISI to identify "hot papers" in its bimonthly publication Science Watch. However, full confirmation of high impact is generally obtained 2 years later. The Scientist waits up to 2 years to select "hot papers" for commentary by authors. Most of these papers will eventually qualify as "citation classics." Of the many conflicting opinions about impact factors, I believe that Hoeffel expressed the situation succinctly. Impact Factor is not a perfect tool to measure the quality of articles but there is nothing better and it has the advantage of already being in existence and is, therefore, a good technique for scientific evaluation. Experience has shown that in each specialty the best journals are those in which it is most difficult to have an article accepted, and these are the journals that have a high impact factor. These journals existed long before the impact factor was devised. The use of impact factor as a measure of quality is widespread because it fits well with the opinion we have in each field of the best journals in our specialty. Dr. Garfield is Chairman Emeritus, Institute for Scientific Information, Philadelphia. Correspondence to: Dr. Eugene Garfield, President and Editor-in-Chief, The Scientist, 3600 Market St., Philadelphia PA 19104, USA; fax 215 387-1266; References Garfield E. Citation indexes to science: a new dimension in documentation through association of ideas. Science 1955;122:108-11. Available: http://garfield.library.upenn.edu/essays/v6p468y1983.pdf Brodman E. Choosing physiology journals. Med Libr Assoc Bull 1960;32:479. Garfield E. Long-term vs. short-term journal impact: Does it matter? Scientist 1998;12(3):10-2. Available: www.the-scientist.library.upenn.edu/yr1998/feb/research_980202.html Garfield E. Long-term vs. short-term journal impact (part II). Scientist 1998;12(14):12-3. Available: www.the-scientist.library.upenn.edu/yr1998/july/research_980706.html Hansen HB, Henriksen JH. How well does journal "impact" work in the assessment of papers on clinical physiology and nuclear medicine? Clin Physiol 1997;17(4):409-18. Garfield E. Is the ratio between number of citations and publications cited a true constant? Current Contents 1976;6(Feb 9). Reprinted in Essays of an Information Scientist. Vol 2, 1974-76. p. 419-21. Available: http://garfield.library.upenn.edu/essays/v2p419y1974-76.pdf Opthof T. Submission, acceptance rate, rapid review system and impact factor. Cardiovasc Res 1999;41(1):1-4. Garfield E. Which medical journals have the greatest impact? Ann Intern Med 1986;105(2):313-20. Available: http://garfield.library.upenn.edu/essays/v10p007y1987.pdf Van Leeuwen TN, Moed HF, Reedijk J. JACS still topping Angewandte Chemie: beware of erroneous impact factors. Chem Intell 1997;3:32-6. Bensman SJ. Scientific and technical serials holdings optimization in an inefficient market: a LSU serials redesign project exercise. Libr Resour Tech Serv 1998;42(3):147-242. Hoeffel C. Journal impact factors [letter]. Allergy 1998;53:1225. [MEDLINE] © 1999 Canadian Medical Association or its licensors
THE ISSN You have certainly already noticed or used this perhaps mysterious code on serials which you read or consult or in references concerning articles or serials : the ISSN. The ISSN is the standardized international code which allows the identification of any serial publication independently of its country of publication, of its language or alphabet, of its frequency, medium, etc. The ISSN is a numeric code which is used as an identifier : it has no signification in itself and does not contain in itself any information referring to the origin or contents of the publication. The ISSN takes the form of the acronym ISSN followed by two groups of four digits, separated by a hyphen. The eighth character is a control digit calculated according to a modulo 11 algorithm on the basis of the 7 preceding digits; this eighth control character may be an "X" if the result of the computing is equal to "10", in order to avoid any ambiguity. Serial publications What is a serial publication? A precise definition, which allows agreement on the exact field of application of the ISSN can be found in the ISO 3297 standard (ISSN) : "A publication, in any medium, issued in successive parts, usually having numerical or chronological designations and intended to be continued with no predetermined end. NOTE : This definition excludes works intended to be published in a finite number of parts.(...) The ISSN is applicable to the entire population of serials, whether past, present or to be published in the foreseeable future. Serials include periodicals newspapers, annuals (reports, yearbooks, directories, etc.), the journals, series, memoirs, proceedings, transactions, etc. of societies." Hence an ISSN can be assigned to any serial publication, whether it is printed or available on any other medium (CD-ROM, floppy disk, electronic publication...). The fundamental criteria which define a serial publication are that its component parts are published successively under the same title for a period of time which is not limited in advance. The ISSN is defined by the ISO 3297 standard The ISSN is defined by a standard, i.e. it is the object of a definition and of standardized application rules internationally adopted in the framework of ISO (International Standards Organization) which groups the official standardization institutions throughout the world. This has allowed from the origin the ISSN to be a tool internationally used in the most diverse frameworks in a coherent and compatible way. The ISSN International Centre is the registration institution officially designated by ISO for the ISSN. The other identification codes The principle of an international standardized identification code exists in other domains. Thus monographs (books) are identified through the ISBN (International Standard Book Number), musical scores by the ISMN (International Standard Music Number), sound recordings by the ISRC (International Standard Recording Code), etc. To each of these codes corresponds a particular and well defined field of application and a logic which is proper to it. It should also be noted that as the ISSN can among others be applied to series of books; a book belonging to a particular series wiil have both an ISSN (identifying the series) and an ISBN (identifying the given monograph as such).
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