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Searching the Topic Field

Enter Topic terms to search for records on various subjects.

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Enter search terms in any order. The following searches are equivalent:

• radioactive decay
• decay radioactive

To search for an exact phrase, use quotation marks. Example: "radioactive decay"

Use wildcards (* $ ?) to find plural and inflected forms of words.

Use search operators (AND, OR, NOT, NEAR, SAME) to prescribe a relationship between terms such as equivalence, exclusion or proximity.

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Implicit AND Operator

Remember that the product uses an implicit AND operator when you enter two or more adjacent terms in most fields. For example:

Entering rainbow trout fish farm in a Topic or Title search is equivalent to entering rainbow AND trout AND fish AND farm. Both queries return the same number of results.

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Search Rules

• AIDS, Aids, and aids returns the same results: case does not matter.

• Enzym* matches enzyme, enzymes, enzymatic, and enzymology.

• Sul*ur matches sulfur and sulphur.

• *Cycline* matches doxycycline, monocycline, and tetracycline.

• *Oxide matches peroxide, sulfoxide, nitric oxide, zinc oxide, and more.

• Vitamin D matches vitamin D.

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Right- and Left-hand Truncation

Both right- and left-hand truncation are allowed when using wildcards (* $ ?) in Topic and Title searches.

You must enter at least three characters after a wildcard when using left-hand truncation and three characters before a wildcard when using right-hand truncation. For example:

• The query *oxide matches terms such as peroxide, sulfoxide, nitric oxide, and zinc oxide.

• The query oxid* matches terms such as oxidation, oxidative, and oxidizing.

• The query *oxid* matches terms such as antioxidant, dioxide, oxidative, and polyphenoloxidase.

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Lemmatization

Web of Science automatically applies lemmatization rules to Topic and Title search queries. Lemmatization reduces inflected forms of a word to their lexical root. With lemmatization turned on, a search term is reduced to its "lemma" and inflected forms of the word are retrieved. As a result, lemmatization can reduce or eliminate the need to use wildcards to retrieve plurals and variant spellings of a word.

For example:

• cite finds inflected forms of the word cite, such as citing, cites, cited and citation.
• defense finds spelling variants such as defense and defence

Lemmatization applies only to English-language search terms.

Stemming

Web of Science also applies stemming rules to Topic and Title search queries. Stemming removes suffixes such as -ing and -es from words in a search query in order to expand the search and to retrieve additional, relevant records. For example, a Title search for vinyl recording will find articles with the term vinyl record.

Stemming and lemmatization are closely related. The difference is that stemming merely drops suffixes such as -ing and -es, while lemmatization makes use of dictionaries that define pairs and clusters (e.g., defense, defence) of words with the same meaning or with a shared morphological structure.

Both lemmatization and stemming applie only to English-language search terms.

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Lemmatization and Quotation Marks

The product does not retrieve synonyms and lemmatized terms when you enclosed your search terms in quotation (" ") marks. For example:

• "mouse" finds records that contain the word mouse but not mice.
• "color" finds records that contain the word color but not colour.

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Lemmatization and Wildcards

The product turns off lemmatization when search terms are used with wildcards. For example, color* finds records that contain the words color, colors, and colorful but not colour, colours, and colourful.

To find all variants of a term, enter both terms using a wildcard separated by the OR operator. For example, color* OR colour* finds both variants.

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Lemmatization and Left-hand Truncation

The product turns off lemmatization when left-hand truncation is used in some types of queries. For example, *valves returns bivalves but not the singular form bivalve.

By adding right-hand truncation to your search, the product returns both plural and singular terms. For example, *valve* returns bivalve and bivalves.

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Lemmatization and Too Many Search Terms

The product turns off lemmatization when your English-language search query exceeds the number of terms allowed in a search. When you exceed the limit, the product returns only exact matches.

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Search Examples

• "Water consumption" finds records containing the exact phrase water consumption.

• Water AND consumption finds records containing the words water and consumption. The two words may appear in the same Topic field or they may appear in different fields.

• Water AND consum* finds records containing the words water, consume, consumed, consumer, consumption, and so on.

• *Water AND consumption finds records containing the words water, freshwater, saltwater, seawater, and consumption.

• Water OR consumption finds records containing either water or consumption or both words.

• Water NEAR/5 consumption finds records containing the words water and consumption within five words of each other.

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Implied AND Operator

The product uses an implicit AND operator when you enter two or more adjacent terms in most fields.

For example, the title search rainbow trout fish farm is equivalent to rainbow AND trout AND fish AND farm -- both queries return the same number of results.

Note: Implied AND does not apply to Chinese-language search queries.

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Using Quotation Marks

Use quotation marks to find exact phrases and to turn off lemmatization and the product's internal synonym finder. For example:

• "soil drainage" finds soil drainage, but not drainage of soil.

• "mouse" finds mouse, but not mice.

• "color" finds color, but not colour.

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Spelling Variations

The product automatically finds spelling variations (such as U.S. and U.K. spelling differences) in Topic and Title search terms.

For example, if you enter color in the Title field, the product finds all records that contain the term color and/or colour in the article title.

To turn off the this feature, enter a term using quotation marks ( "" ). For example:

• Color AND Bird* AND Gene* finds all articles that contain the terms color or colour and bird, birds, gene, and genes.

• "Color" AND Bird* AND Gene* finds only articles that contain the term color, bird, birds, gene, and genes.

Click the link for a list of synonyms.