The most common set of subject headings are those of the Library of Congress. Subject Headings are assigned by various groups so that everything about the same subject is found together. The same idea is applied to subject headings. A thesaurus will help improve the accuracy of your search. But, by going to the thesaurus you may find that academic articles for your “illness” are really found under the controlled term of “disease” or “contagious diseases”. If you expanded and searched for “illness OR sickness” you would return even more results. If you were searching for some illness, would you just enter “illness” as a keyword? You could and you would get some results. This can save time when researching and can produce better results. These terms then are standardized and are used to tag articles and books and thus keep related materials connected by the controlled vocabulary. What that means is that when you look for your word in a thesaurus, the returns will not be all the synonyms of the word, but will be words chosen by librarians, the Library of Congress or some other association, that are used in place of all the synonyms. Many thesauri are built around the idea of controlled vocabulary. Many search engines have built in thesauri that can help you find the right words. When using a search engine, it is often beneficial to look up other words, other keywords, because you want to find ALL the relevant materials. Ī thesaurus is a book typically used to find synonyms or antonyms for known words. Proximity Searching is not used in our WorldCat catalog, but is available in our EBSCO hosted databases and in ProQuest. For example, an article about the death penalty, may have sentences that state the “penalty for such a crime is death.” So this sentence would be found by, but would not be found by the phrase search or. By stating NEAR5 or WITHIN5 you want the search terms within 5 words of each other. WITHIN returns results for the words, in the order stated, within some number of words of each other. NEAR returns results for the words, in any order, within some number of words of each other. With Proximity searching you can look for terms that are NEAR each other or are WITHIN so many words of each other. Proximity Searching is something that also can help narrow down your results. Google automatically assumes AND between all search terms. And OR can be replaced by a vertical line.Īnother comment about Boolean operators and search engines is that you should always check the “help” or “tips” on the search page to know if the search automatically inserts AND or OR between your terms. NOT is replaced with the minus sign, because you are subtracting terms from the results. AND is replaced with the plus sign, because you are adding a required term. In Google these operators can be replaced by math symbols. So, the search engine will find all occurrences of the term, but then remove those that have the second term, the term listed after NOT. NOT simply removes pages that have that term. AND narrows the results to have BOTH terms present. So, if a website only has one of the terms, it will not be listed in the results page. When AND is placed between both words the search engine is looking for all occurrences where BOTH terms are present in the same page. AND, on the other hand, is used to narrow the results. In a way it is committing 2 searches, but putting the results in one list. The search engine is looking for either topic. When OR, in all caps, is placed between two word in a query, the engine will look for any occurrence of either word. These words have specific functions in the search process. Boolean Operators are a set of fixed words, AND, NOT, and OR, that are used in most search engines.
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