CHAPTER 4 INDEXING OPERATION 4.1 DEFINITION The indexing or subject heading operation is the process of assigning to an article the headings from MEDICAL SUBJECT HEADINGS (MeSH), the MEDLARS authoritative vocabulary, which best describe the content and substance as written by the author. 4.2 COORDINATE INDEXING MEDLARS uses a system of coordinate indexing. In coordinate indexing, the concepts in the text of articles are expressed by the combination or coordination of two or more indexing terms, some destined for publication in INDEX MEDICUS and others destined for storage within the computer for future retrieval. The indexing of terms destined for INDEX MEDICUS (IM) will reflect the point of the article, while the computer store will garner either their coordinates (terms which limit or describe or qualify the IM terms) or significant items discussed by the author but which are not necessarily the major point. These latter headings are termed NON-INDEX MEDICUS or NIM headings. Coordination in MEDLARS is achieved by - two or more main headings - a main heading and a subheading - a main heading and a check tag (a pre-determined concept routinely checked in every article) - a pre-coordinated main heading, i.e., one created from a past frequent co- occurrence of two concepts Any article can be indexed by any type of coordination or by a combination of any two or more of the above types. See Figure 4.2 for an illustration of the types using hypothetical titles of articles. The elements of coordination requiring most explanation are the Check Tags (Chapter 18) and the Subheadings (Chapter 19). Many of the following pages will be devoted to explanations of these essential coordinations. TYPES OF COORDINATION IN MEDLARS Two or more main headings Statistics on shock therapy: CONVULSIVE THERAPY (IM) STATISTICS (NIM) Design of intensive care units in psychiatric hospitals: HOSPITALS, PSYCHIATRIC (IM) INTENSIVE CARE UNITS (IM) HOSPITAL DESIGN AND CONSTRUCTION (IM) A main heading and a subheading Metabolism of the liver: LIVER / metabolism Liver pathology in hepatitis: LIVER / pathology (IM) HEPATITIS / pathology (IM) A main heading and a check tag Gastritis in children: GASTRITIS (IM) CHILD (NIM) HUMAN (NIM) Experimental arthritis in dogs: ARTHRITIS (IM) DOGS (NIM) ANIMAL (NIM) A pre-coordinated main heading LIVER GLYCOGEN from LIVER + GLYCOGEN BREAST NEOPLASMS from BREAST + NEOPLASMS HEPATITIS, ANIMAL from HEPATITIS + ANIMAL TUBERCULOSIS, PULMONARY from TUBERCULOSIS + LUNG Figure 4.2 4.3 CONTENT ANALYSIS What are the major points of the article? That is, What concepts in the article are worthy of being called to the attention of the INDEX MEDICUS user? What are the minor points of the article? That is, What concepts would better be stored for future use although they are not the major point? What is discussed as opposed to what is "merely mentioned"? What is the slant of the article with regard to the specialty of the journal, and how does it relate to established indexing principles; i.e., experimental? clinical? pediatric? geriatric? obstetric? veterinary? microbiological? endocrinological? etc. What is the relative status of the general aspects versus the specific? Are the conclusions based on the text or on suppositions or speculations not discussed? Are the concepts picked up for indexing based on the substance of the text and not on the indexer's subjective or personal evaluations? 4.4 ARTICLE EXAMINATION The steps outlined below should be followed in sequence by logic and should be followed routinely for every article to be indexed: Read carefully and understand the title. Read the introduction down to the point where the author states the purpose of his article and correlate it with the title. Absorb but do not necessarily attempt to index the introductory material since this is usually a statement of known facts upon which his present study is based. Note chapter headings, section headings, paragraph headings; italics, boldface; charts, plates, tables, illustrations; laboratory methods, case reports, etc. Headings supplied by the author usually herald the content of the section headed. Select for indexing only those subjects actually discussed (and therefore worthy of retrieval as INDEX MEDICUS citations or in on-line searches) as opposed to those subjects merely mentioned (and of little or no value in retrieval). Read the summary or conclusions of the author to determine whether he achieved the aims set forth in his stated purpose. Weigh conclusions based on the text but do not index implications or suggested future applications. Do not index conclusive statements not supported by discussion in the text. Scan the bibliographic references supplied by the author for clues and further corroborations. Scan the abstract, if there, for items missed in indexing, being careful, however, to locate actual discussions within the text of the article; ignore mere implications. Scan the author's own indexing if supplied or the keywords supplied by the publisher to see whether the concepts chosen are actually discussed in the text and already picked up by the indexer. 4.5 QUALITIES OF THE INDEXING OPERATION In assigning subject headings after following the routine outlined above, the conclusions reached by the indexer should be characterized at all times by these qualities to follow. They represent the basic philosophy of indexing. 4.5.1 Conformity: The indexer must adhere to the content of MEDICAL SUBJECT HEADINGS, the MEDLARS thesaurus, in analyzing the literature, and to its directions in the form of the cross-references provided. He must follow the hierarchy of these headings (the Trees) and the policies governing their use. 4.5.2 Consistency: The indexer must apply consistently the practices he follows in conforming to MeSH and to rules of indexing. He must consistently use headings the same way each time so that a searcher may rely on his practices and even predict their application. Only in this way can the searcher expect to find the same concepts in the same place with reasonable predictability. 4.5.3 Impartiality: The indexer cannot predict what aspect of an article will be of interest to what researcher. He must set aside personal evaluations and opinion and must approach all subjects in all their aspects impartially and without prejudice. 4.5.4 Specificity: MeSH provides both general concepts (like PHYSIOLOGY) and specific concepts (like LIVER REGENERATION). The indexer is committed to the greatest possible specificity: where the subject of an article is specifically on LEUKOCYTES, it is wrong to assign to the article a general heading like BLOOD or BLOOD CELLS. If an article entitled "Parasiticides in gynecology" is in fact on the treatment of trichomonal vaginitis with metronidazole, the main headings will be TRICHOMONAS VAGINITIS and METRONIDAZOLE and not ANTIPROTOZOAL AGENTS and GYNECOLOGY. 4.5.5 Multiplicity: Since MEDLARS is used by many types of research worker and clinician, the indexer will provide for each article as many subject headings as he deems necessary to index the article adequately from all its aspects. This is called multiple-indexing. The specialty approach of the journal being indexed does not restrict the indexer from indexing other aspects in each article. 4.5.6 Veracity: The headings chosen by the indexer must truly reflect the content of the article. The searcher will go unhesitatingly to an article because the headings selected assure him that he will find there information on the subject concerned with the heading used. In other words, the use of the heading DURA MATER implies that in the article cited is noteworthy information on the dura mater. 4.5.7 Judgment: The indexer is obligated to disregard irrelevant or impertinent data without sacrificing impartiality, specificity, multiplicity or veracity. He must draw upon his familiarity with the subject field, the journal in which the article is printed, its quality, its editorial policy, peculiar language or national practices -- any feature of his knowledge and experience with the subject, field, or journal in hand. Especially noteworthy must be his judgment in differentiating worthy discussion from mere mention in passing. He must judge objectively the substantive amount of text worthy of retrieval; he must refrain from an evaluative judgment of the author's work. 4.6 SELECTION OF ARTICLES In selecting articles for indexing, the following instructions will govern the Index Medicus scope and coverage practices: 4.6.1 Index all original articles on medical and biomedical subjects regardless of form or length. Index any original article on any subject -- medical or non-medical -- written by an employee of the United States Public Health Service or the National Institutes of Health. Index also any article -- in scope or not -- carrying a statement that the research was supported by PHS or NIH. See also 18.15.9. 4.6.2 Index all substantive biographies and obituaries (see sections 32.16 and 32.17). 4.6.3 Index all clinico-pathological conferences (see sections 18.11.8 through 18.11.15). 4.6.4 Index reports of scientific material presented at congresses and conferences, of acceptable substance. If a paragraph, or at least several sentences are devoted to each speaker, the report is substantive enough to be indexed. Do not index reports of congresses and conferences concerning committee matters, organizational details, financial reports, etc. Do not index articles in which an author summarizes and comments on what took place at a congress or meeting if the summary includes no more than the names of the speakers and the titles or topics discussed. 4.6.5 Index so-called "editorials" that are in fact lead articles or special articles on substantive material, generally supplied with a bibliography (see section 126.96.36.199). Do not index editorials that resemble the newspaper concept of editorial with possibly only local interest. Do not index "editorializing" editorials. 4.6.6 Index letters to the editor that are substantive and that are documented and that in fact constitute "little articles" (see section 188.8.131.52). 4.6.7 Index all reports of Councils of the American Medical Association and of all national councils or commissions. 4.6.8 Index all directories and membership lists (see section 33.13). 4.6.9 Index all brief articles and short communications in such journals as Nature, Science, and the like, that are on medical and biomedical subjects, despite their brevity. 4.6.10 Index individual items from "Questions and Answers" sections if substantive. Do not index any Question and Answer that is less than one-quarter page long. Items one-quarter to one-half page long may be selected if at least two references are cited. Items with no references given may be selected only if they are at least one- half page long. 4.6.11 Index presidential addresses if they are substantive. 4.6.12 Index society proceedings within a given issue if they are of substance and with no great variation in length within the issue. Do not index proceedings that are little more than expanded abstracts. Such proceedings are indexed in a block with an "overall". 4.6.13 Index formal discussions of articles. A formal discussion is one with a title more distinctive than the designation "Discussion" and with authors indicated formally. This type is listed as a separate item in the table of contents of the issue. Do not index an informal discussion. An informal discussion is one without a distinctive title, identified by only the word "Discussion". Include this discussion within the pagination of the article to which it is attached. See 10.8. Do not index as a separate article a discussion, formal or informal, that follows the last of a series of articles and discusses them all jointly. See 10.8. 4.6.14 Index translations of articles if the original appeared in a journal not in the List of Journals Indexed in Index Medicus. 4.6.15 Index reprints only if the original appeared in a journal not in the List of Journals Indexed in Index Medicus. 4.6.16 Index reprints of classic articles or other classic landmarks in the history of medicine (see sections 184.108.40.206, 17.20 and 32.9). 4.6.17 Do not index non-medical articles in journals indexed selectively (these are indicated by an "s" -- for selective -- in the List of Journals Indexed in Index Medicus). 4.6.18 Do not index signed or unsigned presentations that appear to be nothing more than a recapitulation of another article previously indexed for Index Medicus when it appeared originally. Such articles are brief and recognizable by a statement of the reference or references early in the text. This is usually verified at the end by a full bibliographic reference. 4.6.19 Do not index such regular features as "X-ray of the month", "What is your diagnosis?", "The ECG of the month", "Dermatological iconography" if the presentation is merely an illustration accompanied by little more than a brief reply. Index such features only if the explanation or analysis constitutes a "little article" with substantial accompanying text and references. 4.6.20 Do not index abstracts, condensations or summaries of books, of articles or of proceedings and presentations at congresses, symposia or other meetings. 4.6.21 Do not index book reviews. "Essay reviews" in history of medicine journals, however, are in scope. 4.6.22 Do not index current bibliographies printed in a journal as a regular feature under a monthly rubric if they are derived from a MEDLINE database. Regularly occurring bibliographies may be selected and indexed if they are not explicitly defined as being derived from MEDLINE. 4.6.23 Do not index monthly epidemiological reports. 4.6.24 Do not index hospital reports. 4.6.25 Do not index business or organizational or administrative reports of institutions. 4.6.26 Do not index medical society news or news notes. 4.6.27 Do not index government news releases or news reports of state or national activities published as regular features of supplementary matter within an issue. 4.6.28 Do not index announcements of new drugs by pharmaceutical companies. 4.6.29 Do not index poster papers if they are little more than expanded abstracts. 4.6.30 Do not index advertisements even if they contain substantial text.