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Module 3:
Using "truncation" (i.e.: *?!$#, and more) |
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©2019 by Chris Niemeyer, University of Missouri-St. Louis.
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Module 3:
Using "truncation" (i.e.: *?!$#, and more) |
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©2019 by Chris Niemeyer, University of Missouri-St. Louis.
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Most library databases will let you change a keyword search in a simple yet powerful way.
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cell phones
AND
accidents
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This involves using a special character of some kind. Often, it is an
asterisk (*).
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cell phones
cell phon*
AND
accidents
accident*
*
*
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Using an
asterisk (or equivalent symbol) during keyword searching will hopefully expand search results. This is called keyword "truncation", and is a search capability supported by almost all library databases.
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cell phon*
AND
accident*
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| For instance cell phon* retrieves: cell phone cell phoned cell phones cell phoning Screen5 |
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| Similarly, accident* retrieves: accident accidents accidental accidentally Screen6 |
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It should be obvious that keyword truncation, if used well, can bring about a radical increase in the number of search results.
agricultur*
agriculture
agricultural
agriculturist
etc., ....
econom*
economy
economic
economists
etc., ....
financ*
finance
financed
financial
etc., ....
politic*
politics
political
politiccian
etc., ....
relation*
relation
relations
relationship
etc., ....
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You would especially want to use truncation when you are not finding enough information and need more search results. Otherwise, truncation is useful but NOT mandatory.
agricultur*
agriculture
agricultural
agriculturist
etc., ....
econom*
economy
economic
economists
etc., ....
financ*
finance
financed
financial
etc., ....
politic*
politics
political
politiccian
etc., ....
relation*
relation
relations
relationship
etc., ....
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By the way, you have to be careful when using keyword truncation.
Let's say you were interested in researching a topic that concerned cats. Screen9 |
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| A keyword search like cat* retrieves: catch catsup cattle catalog cathode catapult cataract catering catalytic catamaran caterpillar ... etc., etc., etc.! Screen10 |
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In terms of good keyword searching,
cat* retrieves a ... catatonic catastrophe! Screen11 |
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But this can lead to a dilemma ... what is the best way to use truncation on
cat?
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The answer is... there is NO way of any kind! Absolutely NONE!
With cat it's apparent that truncation is not always appropriate, no matter how powerful a feature it is. Screen13 |
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Instead, with a term like cat, you can forget about truncation and do a search like the one below, which uses 'Boolean' or between both search terms:
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The search below ensures that you will retrieve any record that references any of these two terms.
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Also, many library databases try to take care of simple plurals in keyword searches.
In such cases, merely typing cat will also retrieve cats. It all depends on the database. Screen16 |
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Finally, SOME databases have a special truncation character, often a plus(+) sign, that only searches for single-letter variants of a term.
Thus cat+ retrieves variants like cats (but also Cate and Cato) only. Again, whether such a truncation character even exists will depend on the database. Screen17 |
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By the way, the truncation symbol is not always an asterisk.
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Depending on the database it might be a $ sign.
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... or even an exclamation point!
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It has also been known to be a ?
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It is because of truncation and other reasons that you will sometimes need to be careful when using punctuation or special characters in a library database.
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It's possible the database will misinterpret what you are trying to do and either give you error messages or bizarre results.
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Even simple periods (".
") MIGHT be misinterpreted as everything from decimal numbers to computer codes to another type of truncation.
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Try removing the periods if you are getting error messages or weird search results.
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To reiterate: the appropriate use of an asterisk or other truncation symbol during a keyword search can expand the number of records you might retrieve.
Most library databases offer keyword truncation. Screen26
cell phon*
AND
accident*
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Truncation is powerful but its use is NOT mandatory nor is it always necessary. It works best when you are having trouble finding information.
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cell phon*
AND
accident*
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If you are not sure whether to use an * or ? or another truncation symbol, ask a reference librarian for help! :-)
Screen28. LAST SCREEN!!
cell phon*
AND
accident*
Module finished!
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