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Welcome
Lesson 1: Choosing a Database
Lesson 2: Planning a Search Strategy
Lesson 3: Using Dialog Search Commands
Lesson 4: Managing Search Results
Lesson 5: Refining a Search (Part 1)
Lesson 6: Refining a Search (Part 2)
Lesson 7: Wrapping Up the Course

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Logical Operators

Step 4: Use Logical Operators to link concepts.

Dialog uses logical operators to link concepts: Two common logical operators are OR, AND.

Learn More   Learn More about logical operators.

Logical Operator Definition Example
OR operator Use OR to group synonymous terms when at least one must be present. s ultraviolet or uv or ultra(w)violet
AND operator Use AND to connect terms when both or all must be present. s market(5n)share and tennis(w)equipment

Review

As I have pointed out, planning is an important part of any search session. Remember to complete the following steps as you plan your own searches.

  1. Determine and try to describe the topic in one sentence.
  2. Determine a list of databases likely to cover the topic.
  3. Analyze the topic and identify individual concepts.
  4. Select possible synonyms or alternative terms for each concept.
  5. Decide on use of truncation, proximity connectors, and logical operators.
Coffee Break It's time for a coffee break before you go to the practice exercises.

When your coffee break is over, go on to the Exercises to try writing search strategies on your own.


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Authoritative Answers Enriched by ProQuest

Learn More #3: Logical Operators:

  1. The OR operator is used to retrieve terms that are synonyms or equivalents. For example, the retrieval of INTERNET OR WORLD(w)WIDE(w)WEB consists of all records containing one or both of these terms. OR increases the number of records retrieved-in other words, with OR you always get mORe. If more than one of the terms occurs within a given record, the retrieved set includes the record only once.

    Example:
    select protect? OR shield?




  2. The AND operator retrieves records where two or more search terms or groups of search terms occur in the same record. SELECT PROFIT(W)SHARING AND PRODUCTIVITY retrieves only those records containing all of these words. AND decreases the number of records retrieved since it requires each term to be present for retrieval.

    Example:
    select japan AND export?

    select market(5n)share AND long(w)distance(w)service




  3. The NOT operator prevents records that include unacceptable or irrelevant search terms from being retrieved. The expression PROFIT(w)SHARING NOT DEFERRED(w)PAYOUT(w)PLAN retrieves records that contain the term PROFIT SHARING but excludes those records that also contain the term DEFERRED PAYOUT PLAN.

    Example:
    select eclipse? not solar

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