Abstracting and Indexing' E. J . CRANE Chemical Abstracts, Columbus, Ohio ORDS, like test tubesland table tops, balances and beakers, play an essential role in scientific research. Investigators use them as a means of cooperation, so essential to progress. Abstractors and indexers use them to make tborouzh " coo~eration~racticable. Words are numerous. Languages are numerous. Journals are numerous. In order that the individual may not become swamped in the sea of words and languages and publications i t is the endeavor of abstracting and indexing services to build useful records of scientific accomplishment by putting together in proper sequence the smallest effective number of exactly the right words. The users of abstracts want meat without parsley or other trimmings and the users of indexes are entitled to a complete book of meal tickets. The necessity for brevity greatly increases the problem of making words serve for clear expression and effective recording. The first requirement of a good abstractor is ability to express himself well. He must master the art of clear and concise statement. A good many scientists lack ability of this sort. Complications in the use of the right words are presented not only by the frequent necessity of abstracting from foreign languages (Chemical Abstracts covers papers published in 31 different languages), but also by the complexities of chemical and other scientific no-
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Presented before the Division of Chemical Education of the American Chemical Society. 106th meeting, Pittsburgh. Pennsylvania, September 7. 1943.
menclature. A good abstractor, or a t least his editor must be well informed as to the technical terminology of his field of activity and such a knowledge is still more important to the scientific indexer. Chemistry has many branches and many applications. Chemists specialize and become well informed in more or less restricted fields. Abstracting assignments are best distributed according to special interests; Chemical Abstracts has such a general policy. This is not enough, however. Skill in abstracting must be acquired also. Authors who abstract their own papers do not always turn out good products. An abstract is that which comprises or concentrates in itself the essential qualities of a larger tliing or of several things. The operation of concentration in abstracting should be carried as far as is consistent with clarity and the provision of information which is considered essential. The purpose of an abstract or series of abstracts will, of course, influence the decision as to what is essential. For most purposes informational abstracts are better than descriptive abstracts. By this i t is meant that abstracts which give the more important results and conclusions of a study are usually preferable to abstracts which merely tell what information can be obtained by reference to the original material. Often an informational abstract need be little longer than a descriptive abstract. In a good abstract all information not transcribed is completely and precisely described. Completeness re-
quires inclusion or specific reference to every measurement, observation, method, apparatus, suggestion, and theory which is presented in a paper as being new and of value in itself. For the chemist this means the reporting of all new compounds and all elements, compounds, and other substances for which new data are given. Often an investigator finds it necessary to prepare a novel piece of apparatus or to work up or improve a method which may be of interest aside from the particular investigation in hand. His description of the apparatus or of the method may be more or less buried in a paper principally about something else. It is a special duty of the abstractor and the indexer to see that such information is effectively recorded. Adequate precision is a factor in completeness. Reference to data should be so specific and precise that there will be small chance that the user of the abstract will be misled into thinking that the paper contains the particular information he wants when i t does not, or vice versa. If the general nature of the paper is not obvious, or if there is a formulated broader purpose of the author which cannot be inferred from the title or from the results reported, the abstract should provide such information. The length of satisfactory abstracts varies widely. This length is by no means proportional to the lengths and degrees of importance of the papers being covered. Much depends on the nature of the material being abstracted. A single.brief sentence may adequately report a very important investigation which required many pages of the original paper. On the other hand, a relatively unimportant paper reporting data on a large number of substances may require a long abstract for adequate reporting. Much that has been said about adequate abstracts could be clearly summarized for the experienced indexer by saying that abstracts should be complete from the indexing point of view. Brevity in abstracts is a virtue, but abstractors should be careful not to sacrifice clearness or to resort to descriptive statements alone for the sake of brevity. Sentences should be complete. A style which reads like notes jotted down or like the average telegram is likely to be unclear in spots and should be avoided. In the maintenance of an abstracting service it is well to establish a good many standardized practices as to such details as forms, abbreviations, spellings, and nomenclature. A certain amount of standardization as to the nature of the abstract, style, and references given is also desirable. Abstractors for Chemkal Abstracts are guided by a 29-page booklet which contains 127 rules or directions. A sample rule which illustrates the attention given to detail is Rule 91, which reads: "It is better not to begin sentences with wordlike symbols. such as A, Act, As, He, I and In, since they are apt to be read as words with resulting confusion. Avoid, e. g., 'He was detd. 'As in 4 samples. . .,' 'Act like P a . . .' 'I m a y be present.' "
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The first step in the maintenance of an abstract serv-
ice is, of course, the getting of the material to be abstracted. If times were normal, perhaps the methods of gaining access to papers to be abstracted would not be of general interest. An abstract journal encounters many obstacles in its effort to provide complete worldwide coverage in wartime. An interesting, continuous struggle has made possible a near approach to current completeness by Chemical Abstracts. The whole story cannot be told now, but mention can be made of the fact that as the war has progressed Chemical Abstracts has improved in its coverage for this period instead of going down with the spread and intensification of warfare. A good deal is still being published, and Chemical Abstracts is getting a high percentage of it. The organization of a staff of abstractors overseas, the use of microfilm copying and of the clipper plane, the utilization, with credit, of abstracts published in neutral countries and some from countries far from neutral, and the obtaining by special means of a large number of journals or photocopies thereof are among the methods used. INDEXING
There are, of course, various kinds of indexes, such as author, subject, and formula indexes. The discussion here will be restricted to subject indexes, though there are interesting problems in connection with other kinds. Subject indexing, like abstracting, is both a science and an art. Still more than abstracting, satisfactory indexing requires a pretty good general knowledge of the field into which the subject matter fits and in which it has significance. Furthermore, training and experience are needed in indexing technique. Necessary general qualifications for an effective indexer are good taste, good judgment, and a habit of conciseness and of liberal and comprehensive thought. The best indexers have a sort of instinctive indexing sense. A good memory helps greatly. The lack of good subject indexes is the greatest weakness in scientific and technical literature. A good subject index is truly an index of subjects and not an index of words. Many existing indexes are of the latter type. They are little more than alphabeted lists of the principal nouns in the titles of the literature being indexed. Such indexes are hopeless, for the naturally unsystematic and unstandardized words used by a great variety of authors, or even oftentimes by an individual author, cannot be fitted together to serve as an effective key for a systematic search. Word indexing leads to scattering, omissions, and unnecessary entries. A skilled subject indexer is master of the words which he must use. He knows the nomenclature of his field thoroughly and he thinks in terms of subjects. He takes precautions to be systematic in making entries in his subject index and to provide an ample supply of cross references (very important) in recognition of the difficulties confronting both the indexer and the index user because of the indefiniteness and multiplicity of words with like or similar meanings.
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In deciding on subject entries to be made for an abstract or paper, many factors need to be taken into consideration. Among these are the author's purpose, his point of view, the new data reported, new or modified methods and apparatus used in obtaining these data, significant relations brought out, as between color and chemical constitution in a chemical study of dyes, theories formulated, new substances prepared, suggested or likely uses for new substances, possibilities for the utilization of material, as certain so-called waste material, desirable groupings based on properties, processes or operations, and effects such as industrial poisoning. An illustration of what is meant by point of view in indexing is provided by studies involving chemical reactions. All of the substances involved in a chemical reaction may be significant subjects, as in a study of the mechanism of a certain equilibrium reaction. None of the substances per se may be significant subjects requiring entry, as in the use of a reaction for some purpose (an analytical purpose, for example) in which the reacting substances are really merely reagents of no general interest. Only the product of a chemical reaction may be the subject, as in a study of the manufacture of a chemical product from common starting materials. The starting material may be an additional significant subject in an industrial reaction, if it is unusual or there is involved a question of the utilization of some mineral or waste product. The starting material may be the only significant substance, as in a reaction for the elimination of a noxious by-product. Just as the length of abstracts properly varies widely, the number of subject index entries for abstracts and papers fittingly shows wide variation. Sometimes a single entry is adequate, but in most cases several entries are required for an abstract or a paper and sometimes a very large number of entries may be necessary, as when new information is supplied concerning a long list of enumerated substances. The number of entries required bears little relation to the importance of a paper or abstract. To safeguard completeness in subject indexing, consideration must be given to all of the factors above mentioned as essential to a complete abstract. One of the biggest tasks in the building of a subject index for a chemical abstract journal is the systematic naming of chemical compounds for entry. In a normal year about 25,000 new compounds are reported and new
information is given for many known compounds. Increasingly complex compounds are being studied. If time would permit, I could go on from here to discuss safeguards for accuracy in subject indexing, the relation of completeness to purpose and point of view, the inadequacy of titles as the basis for indexing, the systematic writing of modifying phrases, the arrangement of entries, printing forms, the various types of cross references, the use of inverted cross referhces to safeguard consistency, the movement from general to specific subjects, and the relation of the purpose and field of the material being indexed to the kind of index suitably made. The subject index to an extensive abstract journal is of much importance. A good index is essential to the accomplishmentof the purpose of an abstracting service, for even with carefully classified abstracts information becomes buried without such help. The building of the subject indexes to Chemical Abstracts requires a considerable portion of the time and effort of the editorial staff. Every entry is checked and double checked. In addition to the provision of abstracts and indexes there are certain supplementary services which an abstract journal can perform. Readers frequently need more detail than can be given in an abstract, and help in bridging the gap between abstracts and original papers is often sought. Chemical Abstracts endeavors to furnish adequate help of this sort. The main reliance is our List of Periodicals Abstracted with its key to library files. Modem developments in photoprinting and microfilm copying mean that, in normal times a t least, any chemist anywhere can get almost any paper fairly quickly and a t reasonable expense. Chemical Abstracts does not undertake to maintain a library service, but we do lend our rarer publications. There are special difficulties along this line during these war days and we are sometimes able to overcome them for readers. An abstract journal can also be of help in nomenclature matters. Its indexes should reflect best usage. An abstracting service conducted as is Chemical Abstracts is a good example of cooperative effort. A few do much reading in order that many will need to do only a little reading to keep informed. I have a notion that the many just mentioned would like to join with me in paying tribute to the few. A generous spirit of altruistic serviceis continuously manifestedin the help provided the editor in this work and he regards it as a privilege to be a part of the C. A . family.
