Databases

Database A database is a collection of data arranged for ease and speed of search and retrieval (The American Heritage Dictionary of English Language, 2000). The quality of being "... arranged for ease and speed of search and retrieval" is what distinguishes a database from a computer network.

Database Although databases can be accessed through the Internet, their contents are not retrieved by search engine services (such as Google or Yahoo!). Some databases are available on CD-ROM and networked in some institutions through a subscription

Database (review) Every database contains certain types and amounts of information referred to as coverage. 

Elements of database coverage What kinds of documents? (journals, magazines, book chapters, dissertations, audio files, statistical tables, images, web pages, software applications?) Which disciplines? (sociology, chemistry, music, all, none?) What time [periods]? (the current year? 1950-1990? how often is the database updated? hourly? daily? weekly? monthly? annually?) What languages? (English only? other languages?) Which publication types? (scholarly? popular? trade? all? other?) What is included in the record? (a whole chapter? article? brief description such as bibliographic citation? abstract?) publisher and title?)

Organization of a database Databases store information in tables; tables store records; each record has fields Databases are generally organized by fields, records, and files.

A field is a single piece of information about an object; If the object were an Employee, a field could be First name, Last name, or Date of birth.

A record is one complete set of fields; In an Employee file, there would be one record for John Smith, another record for Mary Brown, and another record for Sue Black A file is a collection of related records.

Database examples Examples of databases you may encounter in your daily life are: a telephone book T.V. Guide airline reservation system motor vehicle registration records papers in a filing cabinet files on your computer hard drive. 

Understanding searches Databases store data or information in tables, just like the one below:

Understanding searches The table allows one to see all the records stored in the database Tables can store many records

A record is all of the data or information about a thing (or a person) A record is all of the data or information about a thing (or a person). Each bit of information is a field.

How many fields are related to this record?

Activity Create a record with fields for a driver’s licence List as many fields as you think is necessary for a drivers licence

Field Searching Most searches (e.g. using a search engine, databases) search for “words anywhere” or “keywords” automatically This type of search retrieves more information with less precision This is known as “recall” searching (it focuses on recalling as much information as possible)

Most retrieval systems allow searching in specific fields (e. g Most retrieval systems allow searching in specific fields (e.g. author, title) and usually refer to this as “advanced” or “expert” searching This kind of searching typically retrieves ...

... less information with more precision (referred to as precision searching)

Think about it If you are a detective and the only clues you have for a missing persons case are the words "red," "blue," and "green,“. Who is the missing person? What kind of search would this be?

Think about it This is keyword searching When you do a keyword search or an "any word anywhere" search in a library catalogue or a database, you can type in words that describe your research topic in any order and retrieve records containing those search terms. A major disadvantage of a keyword search is that it does not take into account the meaning of the words used as search terms, so if a term has more than one meaning (such as "mouse" - computer hardware or rodent?), irrelevant records may be retrieved.

Think about it If you knew your person had a red tie, blue shirt, and a green beret, who would be the missing person? What kind of search?

Think about it This is field searching Field searching allows you to do a "free-text" search within a specific field, such as author or title. Words are searched in all fields unless fields are specified. The fields that are available for searching are a:(author), t:(title), s:(subject), and o:(other), which searches notes, contents, and publishers.

Search techniques There are basic search techniques that are used when searching for information whether using the library resources, databases or the Internet. You would have encountered four pieces of information that are needed when you did the catalogue tutorial.  These are author, title, subject and keyword.

Search by author An author search is used to locate works by the author.  The more information about the author you provide, the more limited your search results will be.

Title search What is a title search?

Title search A title search is used to locate specific titles of books, references, periodicals and other resources.

Subject search A subject search is used to find materials on a specific topic

Keyword search Keyword search is used when the author or title is unknown.  This is different from the subject search.  A keyword search looks for specific keywords in all fields whereas the subject search is limited to a specific subject heading.

Recall vs Precision and Keyword vs Field When you want to find large amounts of information; general information about a topic, how would you search? When you want to find small number of sources on a specific topic e.g. for course assignments etc, how would you search?

Search query Most databases don't understand the natural language we speak and need help understanding what we are looking for. This requires a special set of conventions

Creating a search query Most databases do not understand the natural language we speak. In this regard, a special set of conventions is utilized when doing a search. These include: Conventions Description Quotation marks Around exact phrases (e.g. “Shortwood college") Logical or Boolean operators Connecting words that narrow or broaden a search to include only what you need. Examples: OR, AND, NOT Wildcards and truncation symbols (* # ? !) For terms that have variant forms of spelling or different possible endings. Examples: child* for child, children, childhood, childish, etc. Using parentheses or Nesting Placing terms in parentheses to indicate separate units. (Like an equation, (A or B) not C

Using quotation marks Placing double quotation marks (some databases use single quotes) around a phrase or single word will restrict a search to that exact word or phrase . For example: a search for the term draw will yield results containing that word e.g. drawn, withdrawn, drawing, etc. A search for “draw” will limit the results to just the word draw.

Boolean operators Boolean operators were developed by George Boole, an English mathematician in the 19th century (Gillispie 1970). The operators are: ■ And ■ Or ■ Not These commands can be used to widen or narrow a search

Boolean operators Stringing search terms together using Boolean operators makes searching for various topics easier and more efficient. Using these operators can greatly reduce or expand the amount of records returned. Boolean operators are useful in saving time by focusing searches for more 'on-target' results that are more appropriate to your needs, eliminating unsuitable or inappropriate information. Each search engine or database collection uses Boolean operators in a slightly different way or may require the operator be typed in capitals or have special punctuation.

Boolean operator: AND gives fewer, more relevant results The And operator finds the intersection of your ideas. It: narrows your search; and gives fewer, more relevant results Essentially, it increases relevance while decreasing the number of items in your retrieval listing

Boolean operator: AND The AND operator will return both terms/phrases in the search listing. Example: A search on stock market AND trading would possibly include the following results: - stock market trading; - trading on the stock market - trading on the late afternoon stock market

Boolean operator: AND A Venn diagram can be used to illustrate how the AND operator works with two keywords. The shaded area in the middle is where the two ideas overlap or intersect. This area represents the records in the database that mention both of the search terms, and these are the only records that will be retrieved.

Boolean operator: AND When you use the catalogue or database search terms with AND, it returns only those records that have ALL of your search terms, thus reducing the results.

Activity 1: Using the AND operator You wish to do a search for earthquakes and tsunamis. Use the information below to draw a Venn diagram to indicate the number of results you would possibly obtain from using the AND in your search: There are 100 articles/records in the database 24 articles are on tsunamis; 12 of these include earthquakes that follow; 6 on volcanoes; 4 on hurricanes 22 articles on hurricanes; 15 on tsunamis, earthquakes and hurricanes 21 articles on volcanic eruptions; 9 include earthquakes There are 33 articles on earthquakes; 5 include tsunamis

Activity 2: AND operator If you wanted to search for three terms, earthquakes, tsunamis, hurricanes: How would you record your search using the AND operator? Using the previous database information, use a Venn diagram to depict the above search and indicate the possible number of results the search would return.

Boolean operator: OR The OR operator will return either term in the returned search listing. The OR operator broadens your search, retrieving more results while decreasing relevance. Example: A search on ecology OR pollution would possibly include the following results: documents containing the world ecology (but not pollution) and other documents containing the word pollution (but not ecology) as well as documents with ecology and pollution in either order or number of uses

Boolean operator: OR A Venn diagram can be used to illustrate how the OR operator works with keywords. When you use OR to combine terms, it broadens your search by having the search engine return at least one of your search terms. The OR operator is best used when combining synonyms or key words that relate to the same topic, adding comprehensiveness to your search. .

Boolean operator: NOT The NOT operator disregards those results which contain the word following NOT; i.e. the first term is searched, then any records containing the term after the operators are subtracted from the results. Example: A search on Mexico NOT city would possibly include the following results: - New Mexico; - the nation of Mexico; - US-Mexico trade; The search would not return Mexico City or This city's trade relationships with Mexico

Boolean operator: NOT A Venn diagram can be used to illustrate how the NOT operator works with keywords. The Not operator excludes ideas from your search, narrowing your results and increases relevance. When you use NOT operator, it limits your search by excluding all records in which your search term is combined with the unwanted term. The NOT operator must always be the last Boolean operator you employ.

Activity: Using the quotation or Boolean operators Visit the Ebscohost database

Sources Lanning, S. (2012). Concise guide to information literacy. ABC-CLIO, California, USA What is a Boolean Operator?" Alliant Libraries. Retrieved from http://library.alliant.edu