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Boolean Searching. Boolean searches are carried out using terms like AND, OR, NOT. By adding these “operators” you tell the database what words the results.

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Presentation on theme: "Boolean Searching. Boolean searches are carried out using terms like AND, OR, NOT. By adding these “operators” you tell the database what words the results."— Presentation transcript:

1 Boolean Searching

2 Boolean searches are carried out using terms like AND, OR, NOT. By adding these “operators” you tell the database what words the results should or should not precisely contain. So you are defining the connections between your keywords. These essentially narrow or expand your search. As they connect words you are more likely to find relevant and focused results. Most web resources require you to always use CAPITAL LETTERS when typing any Boolean operator. What does Boolean searching actually mean?

3 Boolean searching is based on an algebraic system of logic formulated by George Boole (1815-1864) He was a 19th century English mathematician who in 1847 created a mathematical logic foundation which made smarter and faster searching. Further information at: http://en.wikipedia.org/wiki/George_Boole http://www.businessdictionary.com/definiti on/Boolean-search.html#ixzz3S18FtQY3 Where does the word “Boolean” come from?

4 You will have no trouble finding results but you have lots and lots and lots of them. You will have to spend time glancing through the results list and wonder why some of them have appeared based on your keywords. They do not look useful at all! Many library databases and journal packages have complicated indexes built into them. So they are different to searching on a web search engine like Google. Understanding savvy techniques like Boolean will help you quickly locate relevant information. So if you want your results to be more precise and save time then this PowerPoint will show you what operators exist. Why use Boolean operators?

5 You probably already use AND as some resources automatically add it in. AND is sometimes indicated with a plus + sign. When you apply your keywords with AND you are informing the resource that both words must appear. This limits or narrows your results as both words must be there. A good time to use this connector is when your initial keyword search finds too many irrelevant results. So you can use it to refine further. However although your search terms are included in the results, they may not be connected together in the way you want. The use of AND marketing footwear Search results for marketing and footwear This intersection of both words is your results list which features both marketing AND footwear

6 The use of OR When you apply your keywords with OR you are informing the resource that the appearance of either is ok. So this Boolean operator expands or broadens your search. So every page or record must have at least one of the keywords on it. You are giving the resource a choice; either that word OR that word. A good time to use this connector is when your initial keyword search finds too few results. So you can use it to widen your search. It can be a time saver as you can add in different words which have similar meanings; instead of running each search separately. renewable sustainable Search results for renewable OR sustainable The intersection of both words as well as the keywords appearing separately make up your results list.

7 The use of NOT When you apply your keywords with NOT you are excluding certain words from your search string. This narrows your results by not returning hits that contain the excluded words you have chosen. NOT is sometimes indicated with a minus sign -, AND NOT or ANDNOT. It excludes the keyword that follows it. A good time to use this connector is when you scan the first couple of results pages and see numerous irrelevant hits. example: cloning NOT sheep Search results for conservative NOT liberal This section indicates results on conservatives but exclude those that discuss liberals. conservative liberal

8 Quotation marks especially if it is a phrase You can add “quotation marks” to your words. This means the platform will search for them as a phrase in the exact order you type them. This narrows your search. It is good for titles and multi-word terms. “Martin Luther King”“working families”“higher education”

9 Truncation A truncation or stemming symbol allows you to search for all of the words with the same root. To use truncation, enter the root of a word and put the truncation symbol at the end. So for root words with multiple endings you can search for them all at the same time. The truncation symbols vary in each resource so it is worth looking at the online help facilities to make sure you are using the correct one. They can include *, !, ?, or # child* = child, childs, children, childrens, childhood bank* = banks, banking, bankers, bankrupt. advert* = adverts, advertising, advertisement, advertised. sun = suns, sunshine, sunny, sunlight.

10 Search order The online resources will follow the operators and keywords you enter. Please be aware of the logical order in which the Boolean operators are processed. They will normally recognise AND as the main operator first. This has an effect on your search results depending on how you have entered your keywords and operators. E.g. marketing AND Tesco OR Walmart This will find hits that include both marketing AND Tesco as well as any record with keyword Walmart (regardless of whether the record contains the other two terms) marketing Tesco Walmart

11 Nesting and Parentheses You can ensure your keywords and operators are processed correctly by applying certain techniques. It is a complex searching technique but can work well in some online resources. The application of (brackets) ensures the order and priority of search terms. e.g. marketing AND (Tesco OR Walmart) Learn* AND (teenager* OR “young people”) AND (“higher education” OR unversit*)

12 Near If you want to locate specific words in close proximity to each other. Each online resource varies but some locate hits when words are around ten keywords apart. e.g. If you want to find records that either contain the word “alcohol" near the word “addiction" or contain the words “alcohol" near the word “dependency" you should use: (alcohol NEAR addiction) OR (alcohol NEAR dependency)

13 Wildcards operators This is similar to truncation and allows you to substitute a character within a keyword. This is really useful if a word is spelt differently in different countries or languages but has the same meaning. By using a wildcard you make sure variant spellings are not missed and you don’t have to repeat your search twice. They are normally denoted as a hash symbol # or a question mark ? Again each online resource is different so please check the help section. e.g. gr?y searches for grey, gray ?nquiry searches for enquiry, inquiry Wom?n searches for women, woman Colo?r searches for color, colour Organi?ation searches for organization, organisation

14 Acronyms You might also want to consider if your search terms might be an acronym. Certain keywords can be shortened and made into a set of capital letters. These are called an acronym. By knowing the acronym and full term you can widen your search to look for both. e.g. IMF OR “International Monetary Fund” NATO OR “North Atlantic Treaty Organization” HIV OR “human immunodeficiency virus”

15 Applying Boolean to your search topic If you were interested in “Consumer spending habits on biscuits in the UK” you might brainstorm your keywords first then think about how to apply those words to form excellent search strings Consumer CustomerPublic Spending ExpenditureBehaviourChoice Biscuits Cookie Chocolate biscuit PretzelWafer UK United Kingdom UK Great Britain

16 Brainstorm your keywords based on your topic Think about which information sources you are going to use Apply your keywords and look at the results list Add in Boolean operators to make the list more relevant/precise Remember different databases will have their own rules so make sure you are using the correct symbols and truncation. Top tips


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