LIR 10 Week 7

Boolean Searching and Online Periodical Databases

LIR 10 search methods so far…

• You’ve searched the OPAC for Library of Congress subject headings to find books on your topic.

• You’ve browsed through periodical indexes for subject headings and subheadings.

• You’ve searched reference books for information about your topic in the book’s index or for alphabetical entries in the main body of the book.

• Now you’re ready to create your own searches using Boolean logic!

Constructing Searches with Boolean Logic

• Boolean logic is the term used to describe the logical relationship among search terms. “Boolean” refers to the 19th century Irish mathematician George Boole.

• Boolean logic consists of three logical operators:

• OR• AND• NOT

OR

• OR widens a search by instructing the computer to look for every record that includes any of the search terms specified in the statement.

• The OR operator is most commonly used when there are synonyms for a search concept that should be considered.

• For example, let's say you are interested in conducting a search for information about the theater. You might enter the search statement:

theater OR drama OR performance

OR

The Venn diagram below illustrates the search.

• This search instructs the database or search engine to give you all the articles that include the word theater or

• all the articles that include the word drama or

• all the articles that include the word performance or

• all the articles that include any one term, or both, or all three.

theater OR drama OR performance

OR

The more terms combined in a search using OR logic, the more records will be

retrieved

AND

• Use AND to narrow your search. Using AND instructs the database or search engine to retrieve only the records that contain all the search terms that you have specified in your statement.

• For example, if you are interested specifically in improvisational theater, you would enter the search:

improvisational AND theater • Your “recall” (search results) should include articles with

both the words improvisational and theater, in any order. If an article contains only the word improvisational, or if it only contains the word theater, it won't appear in your search results.

AND

The Venn diagram below illustrates the search.

• This search instructs the database or search engine to give you all the articles that include the words improvisational and theater.

• The grey section represents the intersection of the two terms. All search results come from that intersection.

• Articles that include the word improvisational without the word theater, and vice versa, will not be included.improvisational AND theater

AND

The more you use AND, the narrower your search results will become.

NOT

• The NOT operator allows you to exclude records with certain words from your search. Word order is very important when using the NOT operator in a statement. For example:

theater NOT improvisational• will return all the records that contain the

word theater except the ones that also contain the word improvisational.

NOT

The Venn diagram below illustrates the search.

• This search instructs the database or search engine to give you all the articles that include the word theater but do not include the word improvisational.

• The grey section represents the records that would be returned by the search.

• Articles that include the word theater that also include the word improvisational would not be included. theater NOT improvisational

NOT

Using NOT can be tricky. It is possible to exclude documents that may in fact be

relevant.

Summary

• OR retrieves the largest amount of search results. Any and all terms included will be retrieved.

• AND narrows the search results to the intersection of the terms.

• NOT narrows the search by excluding the search term specified.

Precision vs. Recall

• PRECISION equals the number of articles that are directly related to a topic that you retrieve as a result of your search.

• RECALL equals the total number of articles that are peripherally related to the topic that you retrieve as a result of your search.

• When you narrow your search, you hope to increase your precision.

• When you broaden your search, you hope to increase your recall.

Precision vs. Recall

The research process involves adjusting these factors until you get the precise information you need to answer your question, and until you retrieve a sufficient amount of information about it to support your paper.

Online Periodical Resources

• Access SRJC databases on campus or from home:

http://www.santarosa.edu/library/ftdb

• Apply for a PIN

• Start searching!

Subscription Databases vs.

Internet Search Engines • Subscription

databases contain citations and entire articles (usually called full text).

• Thousands of magazines, newspapers and other documents are represented in each database.

• Internet search engines will search for web pages, images, PDF documents and other files available on the Internet.

• Search engines offer limited “precision.”

Different Databases for Different Needs

• Aggregators or Vendors: companies that provide databases.

• The same aggregator or vendor may have different versions of its databases that it markets to different types of institutions or organizations (Old Navy vs. Prada model).

• For example, the ProQuest Newspaper database you search on the public library’s web page will contain different content than the ProQuest Newspaper database you search at SRJC.

The Right Database for the Right Information Need

• General vs. Subject-specific

• Look at the Database Description (the round “i” icon next to the database name)

• Check the date range, periodicals covered and “help” screen

• After selecting a database, look at the opening screen: take a minute to see “where you are” in the database

Databases for Week 7

ProQuest Magazines and Newspapers

• Articles from thousands of popular magazines and newspapers, as well as scholarly journals, news services and other information sources.

• Covers over 560 U.S. & world newspapers.

• Covers over 2,500 magazines and journals.

Expanded Academic ASAP• Full text of articles in over

2,150 magazines and scholarly journals.

• Citations only for an additional 1,355 magazines and journals.

• Over 1,700 scholarly or "refereed" journals are included.

Homework for next week

• Use either ProQuest or Expanded Academic ASAP.

• Use Boolean operators to find articles on your topic.

• Answer the questions on your worksheet.

• Print out the first page of the article you choose and include it with your worksheet.