Autostemming

Stemming determines the suffixes of words and allows you to search for the term as entered, the root word, and other words formed with other possible suffixes. For example, if you enter the term controllers, you get results for the following:

Autostemming provides you with much broader search results as the system stems all search terms except for author names and words in quotation marks and/or braces. You do not need to search for all the variations of the terms in your search query as they are provided in the results.

Autostemming is available in Quick and Expert searches.

Autostemming and Proximity Operators

Autostemming can be used with proximity operators since all of the terms are automatically stemmed.

For example, electric ONEAR/0 guitars finds the following results:

Autostemming and Spelling Variations

Autostemming does not find variants between British and American spellings.

For example, color does not find colour or coloured.

However, colour will find colourful or colours.

To be inclusive, in this case you would need to search for color or colour.

Turn off Autostemming

  1. From the Quick and Expert search forms, click the Autostemming tab. The Turn autostemming off check box displays.
  2. Select the Turn autostemming off check box to disable the Autostemming feature.
  3. Clear this check box to turn the autostemming feature back on.

Improve Stemming Precision

In order to improve the precision of stemming results, you can apply stemming to specific terms in your search query rather than to allow the autostemming feature to stem all terms except author names and words in double quotation marks and/or braces.

  1. Select Autostemming off to turn off the autostemming feature.
  2. Use a dollar sign ($) in front of each search term in your search query that you want to be stemmed.

    For example $electric $motor finds the following results:

    electric motor, electrical motors, motor and electrically driven vehicle etc.

    However, $electric motor finds the following results:

    electric motor and electrical motor, but not

    electric motors or electrical motors

    as the word motor is not stemmed in this case.

    Note

    You cannot use proximity operators with stemming unless all the terms are stemmed. There will be inconsistent search results if only specific search terms are stemmed in a search query.

    For example, $control ONEAR/0 drug or control ONEAR/0 $drug will provide inconsistent search results because not all of the search terms are stemmed in these cases.

    In order to provide consistent search results, autostemming must be enabled, or the search query must have all terms stemmed.

    For example $control ONEAR/0 $drug will produce consistent search results as both search terms are stemmed.

    Using truncation or wildcards turns off the autostemming feature. If you want your results stemmed when using truncation or wildcards, use the dollar sign ($) to manually stem each search term in your query.

 

 

 

 

 

 

 

Copyright © 2018 Elsevier B.V. All rights reserved. Elsevier Properties S.A. Terms and Conditions