HIST 3360: London from 'Great Wen' to World City

Boolean operators form the basis of mathematical sets and database logic.

• They connect your search words together to either narrow or broaden your set of results.
• The three basic boolean operators are: AND, OR, and NOT.
• In CLIO and some other databases you DO have to use capital letters
• This type of search is possible in most library catalogs and databases, but Google and other Web search engines do not carry out OR and NOT searches properly.

Why use Boolean operators?

• To focus a search, particularly when your topic contains multiple search terms.
• To connect various pieces of information to find exactly what you're looking for.

AND

• The operator AND narrows the search by instructing the search engine to search for all the records containing the first keyword, then for all the records containing the second keyword, and show only those records that contain both.
• In many, but not all, databases, the AND is implied. 
  • Though all your search terms are included in the results, they may not be connected together in the way you want.
  • College students test anxiety  is translated to:  college AND students AND test AND anxiety. The words may appear individually throughout the resulting records.
• You can search using phrases to make your results more specific.
• For example:  "college students" AND "test anxiety". This way, the phrases show up in the results as you expect them to be.

OR

The operator OR broadens the search to include records containing either keyword, or both.
The OR search is particularly useful when there are several common synonyms for a concept, or variant spellings of a word.

medieval OR "middle ages"
 

NOT

Combining search terms with the NOT operator narrows the search by excluding unwanted terms.

Parenthesis 

• You can enclose search terms and their operators in parentheses to specify the order in which they are interpreted. Information within parentheses is read first, then information outside parentheses is read next. For example,
• When you enter (mouse OR rat) AND trap, the search engine retrieves results containing the word mouse or the word rat together with the word trap in the fields searched by default.

Here are some examples using combinations of the three operators & parenthesis

• puritans AND women AND (massachusetts OR connecticut OR "rhode island" OR "new hampshire")
• (adolescen* OR teen*) AND (cigarettes OR smok*)
• reagan AND "star wars" NOT (movie OR film OR cinema OR "motion picture")
• "zora neale hurston" AND (correspondence OR letter* OR diar* OR autobiograph* OR memoir*)

• Use "quotes" for a phrase
  • “emily bronte” will find results with the phrase “emily bronte” but not those that have “emily smith” or “charlotte bronte”
• To find variant endings of a word, use * for truncation.
  • child* finds childhood, children and child’s, as well as child
• However, don’t shorten the root word too much, or you will also find irrelevant results.
  • poli* finds politics and political, but it also finds police and polite.

An authoritative source will have a clear, unbiased reason for existing.

• Are the authors’ purposes and goals clear?
• Is the source trying to inform, teach, persuade, entertain, or sell a product?
• Does the language and tone seem unbiased and objective, or is it subjective, emotional, and personal?
• Is there evidence of bias? Does the source or publisher represent a particular point of view?
• Is it possible to determine who funds the organization that produced the source? Does the author or publisher stand to gain something for the position they chose on the topic?
• Are there excessive amounts of advertisements?

An authoritative source will identify its authors and their credentials.

• Is the author of the text clearly indicated?
• Are the author’s credentials (degree, profession, experience, etc.) indicated?
• Are the author’s credentials relevant to the topic?
• Does the author have any particular organizational affiliations (universities, government, etc. )?
• Does the author or publisher provide any contact information (e-mail, telephone, mailing address)?
• For websites: Does the URL reveal anything about the author or host (eg: .com, .edu, .org, .gc.ca)?

An authoritative source will provide reliable, correct information.

• What is the source of the information provided?
• Does the source provide evidence to back up its claims? Can this evidence be independently verified in other sources (references, links, etc.)?
• Is the text free from spelling, grammar or typographical errors? Is the source free from factual errors?
• Is there anything else suspicious about the source?
• For websites: Is the host of the page clearly identified? Is the host well-known and can the host’s identity be independently verified (e.g. via Google)?
• For scholarly sources: has the information been peer-reviewed?

In addition to being authoritative, a source must also be relevant to your particular needs.

• Does the information relate to your topic or answer your question(s)?
• Who is the intended audience? Is the text at an appropriate level for academic research?
• Have you looked at a range of sources before determining this is the one you will use?
• Would you be comfortable citing this source in a research paper?

The timeliness of the information provided by a source can be very important.

• Is the date of publication indicated?
• Is the date when the source was last revised or updated indicated? Was it updated recently?
• Does your topic require current information, or will older sources work as well?
• Is there more recent information on the topic, and if so does it differ from the information provided in the source you are evaluating?
• For websites: are the links on the page up-to-date? Do they function properly?