Indexing word / subject index

In addition, the website www.math.com has helpful mini lessons and further practice problems. Click on Percents under Hot Subjects. Then click on numbers under the word percent. Follow along with the lesson explanation and then practice problems. To explore the part/whole relationship of percents and how they are related to decimals and fractions, try http //matti.usu.edu/nlvm/nav/index.html. Click on the Virtual Library. Then choose Numbers and Operations under the column 9-12. Scroll down, and then click on Percentages. 

In words, the values of one variable (divisor, index k) are used to divide the remaining variables of each object. Thus, the transformed values are related to one variable (which is lost for further analysis), and consequently they have a different interpretation. Moreover, it is rather subjective which variable is used as divisor, and subsequent results will depend on this choice. 

Most public libraries subscribe to database services such as InfoTrac or EBSCO that index articles from hundreds of general-interest periodicals (and some moderately specialized ones). The database can be searched by author or by words in the title, subject headings, and sometimes words found anywhere in the article text. Depending on the database used, hits in the database can result in just a bibliographical description (author, tide, pages, periodical name, issue date), a description plus an abstract (a paragraph summarizing the contents of the article), or the full text of the article itself. 

Finally, I should mention a word about filing technical papers. It is tempting to keep a file of papers by subject, and this is satisfactory for collections of 100 to 200 papers, but beyond that a more systematic method is necessary. Ben Wylie, my dissertation advisor, filed his papers by unique serial number and uses an ingenious system of cross-referenced index cards for retrieving papers by author, title, or subject. I ve adopted the same serial-number system, but I use a computer database to cross reference the file records. I use that database online to help locate a needed reference at a moment s notice. 

True subject indexing carefully controlled leads to consistency in an index, and consistency is of much importance. Word indexing leads to omissions, scattering. 

The web is the most popular Internet application. It allows easy links to information and files which may be located on computers anywhere in the world. The WWW allows access to millions of home pages or websites , the initial point of reference with companies, institutes and individuals. Besides their own text and images, these contain hypertext links , highlighted words or phrases that you chck on to take you to another page on the same website or to a completely different site with related subject material. Certain sites specialize in such links, acting like indexes to other websites these are particularly useful. 

You are unlikely to delve into the primary literature for these purposes -books and reviews are much more readable If a lecturer or tutor specifies a particular book, then it should not be difficult to find out where it is shelved in your library, as most libraries now have a computerized index system and their staff will be happy to assist with any queries. If you want to find out which books your library holds on a specified topic, use the system s subject index. You will also be able to search by author or by key words. 

Possibly more important than anything you might learn from this book is how to study it. First, read every word in the index. Unconciously, this will feed data into your brain and give you a subconcious overview of the subject. It will also help you later to find subjects which are not cross-indexed to your satisfaction. 

Early chemical indexing did not approach the 67 words of index per 100 words of text which is approximately the present level for Chemical Abstracts. But gradually indexers sensed more of the searcher s needs as chemical literature grew in bulk and complexity, subject indexes made halting but persistent efforts to keep... 

Let us first consider the subject index of Chemical Abstracts, the most revealing of the chemical indexes. Some idea of the indexing system is given in the introduction to each annual index, but the system is fully explained in the 1945 issue (6). The first consideration is that subject indexing is used rather than word indexing. For instance, a book entitled "Chemists Handbook would be word-indexed under "Chemist but subject-indexed under "Chemistry, if the subject matter were chemistry rather than chemists. Another book on "Who s Who in Chemistry would be word-indexed under "Chemistry but subject-indexed under "Chemists. ... 

The system of subject indexing in British Abstracts [which ceased publication with the December 1953 issue] is described in the 1948 index (4). Subject indexing is used rather than word indexing, but the range of subject headings listed is very much narrower than that of Chemical Abstracts. These subject headings or key words do not always include the chemical name but are "the words under which the information is most likely to be sought. ... 

Entries under a formula heading consist of the formula, in bold-faced type the name as it has been used in the subject index, in lightface roman type—that part of the entry in this type is the exact equivalent of the formula given occasionally a modifying phrase or word in italics which represents that part of the compound indexed not represented in the formula, as "Na salt or di-HCl and the column-fraction reference to the abstract proper. 

The above is just an indication of the use of indexes. More detailed information on this important subject is given in the chapter on indexes in the A Guide to the Literature of Chemistry by Crane, Patterson, and Man (10). The more one uses an index the more one learns about it, particularly if the index is approached receptively. The importance of indexing and the part it plays in giving information can be judged by the finding of Crane (9) that 700 words of indexing are necessary for each 1000 words of abstract. 

Subjects, not words, are indexed by CA. There is a wide difference. Word indexing leads to omissions, scattering, and unnecessary entries. True subject indexing avoids these defects. Subject indexing means, of course, that the words used in the index may differ from those used in the abstract. For the best results index users must be subject-minded rather than word-minded, so to speak. 

Cross references, abundantly used in the subject indexes to CA, not only guide the index user from place to place as a help in making his search a thorough one, but also overcome some of the limitations of words as an exact and definitive medium of expression. It pays good dividends to use cross references in CA indexes more than inexperienced index users sometimes do. The CA master cross-reference file contains more than 60,000 entries. 

Because chemical names are subject to a certain amount of developmental change and because complex compounds are difficult to name and lend themselves to correct naming in more than one way, CA as long ago as 1920 adopted the practice of indexing compounds by systematically arranged molecular fonnulas (these do not vary), but it did not abandon the use of words also in the indexing of compounds. Readers are given their choice, with both the index by names and the index by formulas made complete. Entry in the Formula Index of the simpler and commoner compounds in the form of cross references to the Subject Index is re-... 

Many subject indexes are defective in being too much indexes of words rather than of subjects. Although this criticism does not apply to present subject indexes of Chemical Abstracts, they are deficient for the most effective searching for particular kinds of analytical methods. 

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