Unit B Constructing Complex Searches Internet Research Third Edition

Internet Research, Third Edition - Illustrated Objectives Understand Boolean operators Narrow the search with the AND operator Expand the search with the OR operator Restrict queries with the AND NOT operator

Internet Research, Third Edition - Illustrated Objectives Use multiple Boolean operators Search with filters Combine Boolean operators and filters Use metasearch engines

Internet Research, Third Edition - Illustrated Constructing Complex Searches Complex searches –searches using Boolean operators to expand, narrow, and restrict the results

Internet Research, Third Edition - Illustrated Understanding Boolean Operators Boolean operators are special words or symbols used to connect keywords and phrases in a search There are three common Boolean operators –AND –OR –AND NOT

Internet Research, Third Edition - Illustrated Terms to Use Boolean operators –words and symbols that connect keywords & phrases Default operator –the Boolean operator used automatically by a search tool

Internet Research, Third Edition - Illustrated Clues to Use Always use all capital letters for Boolean operators Always use all capital letters for Boolean operators

Internet Research, Third Edition - Illustrated Understanding Boolean Operators Understanding Boolean Operators Define the relationships between keywords and phrases and help focus search results Either narrow or broaden a search, thereby decreasing or increasing the number of results

Internet Research, Third Edition - Illustrated Understanding Boolean Operators Understanding Boolean Operators Based on Boolean logic –a mathematical syntax, in which keywords act as nouns and the operators act as conjunctions, joining keywords in a way that search tools can interpret

Internet Research, Third Edition - Illustrated Venn Diagrams Venn Diagrams Venn diagrams are used to illustrate Boolean logic and searches using Boolean operators –were created by John Venn to explain visually what George Boole, creator of Boolean Algebra, had described symbolically: the intersection, union, and exclusion of setsthe intersection, union, and exclusion of sets

Internet Research, Third Edition - Illustrated Venn Diagrams Each circle represents a set or Web pages returned by one concept in a search When circles overlap it indicates some pages are returned for both concepts. The area of overlap is the intersection of the sets

Internet Research, Third Edition - Illustrated Venn Diagrams When a search returns all of the pages in both circles, it is the union of the sets.

Internet Research, Third Edition - Illustrated Venn Diagrams One set Intersection of two sets Union Using Venn diagrams to represent Boolean searching

Internet Research, Third Edition - Illustrated Clues to Use When uncertain about which Boolean operator to use in a search, sketch a quick Venn diagram When uncertain about which Boolean operator to use in a search, sketch a quick Venn diagram Label it with your search terms and it will become clear

Internet Research, Third Edition - Illustrated Terms to Use Syntax –rules in a language, like grammar, that standardize usage; in computer searching, syntax, like Boolean logic, governs the form queries must take to instruct a search tool to perform a certain function Venn diagrams –drawings used to represent Boolean logic and searches using Boolean operators

Internet Research, Third Edition - Illustrated Using the AND Operator The AND operator narrows or limits your search, thereby decreasing the number of search results

Internet Research, Third Edition - Illustrated Using the AND Operator Use AND when –you need to focus your results –you need to force the search of a stop word

Internet Research, Third Edition - Illustrated Using the AND Operator An intersection of two sets occurs when you use AND: Web pages containing apples apples plums Web pages containing plums Web pages containing both apples and plums.

Internet Research, Third Edition - Illustrated Clues to Use Most search engines accept + instead of AND Some search engines require using + instead of AND Always leave a space in front of + Never leave a space after +

Internet Research, Third Edition - Illustrated Using the OR Operator The OR operator expands or broadens your search, thereby increasing the number of search results

Internet Research, Third Edition - Illustrated Using the OR Operator Use OR –when you need to broaden your results –to combine synonyms and related words

Internet Research, Third Edition - Illustrated Using the OR Operator A union of two sets occurs when you use OR: A union of two sets occurs when you use OR: Web pages containing either apples or plums. apples plums

Internet Research, Third Edition - Illustrated Using the AND NOT Operator The AND NOT operator limits or narrows your search by excluding or restricting a concept from your results, thereby decreasing the number of results

Internet Research, Third Edition - Illustrated Using the AND NOT Operator Using the AND NOT Operator Use AND NOT –when finding too many irrelevant results –to exclude a concept from your results

Internet Research, Third Edition - Illustrated Using the AND NOT Operator Using AND NOT excludes a concept: apples plums Web pages containing apples but not plums. Web pages where the sets intersect are excluded, even though they contain apples, because the results must exclude any page containing plums. So, you are left with pages that contain apples without containing plums.

Internet Research, Third Edition - Illustrated Clues to Use Most search engines accept - instead of AND NOT Some search engines require using - instead of AND NOT Always leave a space in front of - Never leave a space after -

Internet Research, Third Edition - Illustrated Using Multiple Boolean Operators Using multiple Boolean operators will provide more focused results

Internet Research, Third Edition - Illustrated Clues to Use When using multiple Boolean operators, use parentheses ( ) to separate concepts and to force the order in which your search is performed

Internet Research, Third Edition - Illustrated Terms to Use Forcing the order of operation using parentheses in a complex query –to force the search tool to perform the part of the search inside the parentheses

Internet Research, Third Edition - Illustrated Searching with Filters Searching with filters narrows your search by telling search tools to screen out specified types of Web pages

Internet Research, Third Edition - Illustrated Searching with Filters Language filter limits search to language you choose File format filter limits search to file format you choose Date filter limits search to pages updated within a specified time period

Internet Research, Third Edition - Illustrated Searching with Filters Location filter limits search to pages containing your keywords in the location you choose Domain filter limits search to a specified domain

Internet Research, Third Edition - Illustrated Searching with Filters Censoring filter limits search by attempting to filter potentially offensive pages

Internet Research, Third Edition - Illustrated Combining Boolean Operators and Filters Use both Boolean operators and filters when you need to perform very specific searches to return the most relevant results

Internet Research, Third Edition - Illustrated Using Metasearch Engines Use metasearch engines –when you need to see the most highly ranked results from multiple search engines –to identify which search engine might be best for a specific search

Internet Research, Third Edition - Illustrated Using Metasearch Engines Metasearch engines: –Dogpile –Fazzle –Ixquick –MetaCrawler –Search.com –Vivisimo

Internet Research, Third Edition - Illustrated Clues to Use Since metasearch engine results can be inconsistent, verify an engine you want searched was actually used for your search If you don’t know that the metasearch engine you are using can translate your query effectively, use simple searches

Internet Research, Third Edition - Illustrated Complex Searches Constructing complex searches includes –understanding Boolean operators –using AND to narrow a search –using OR to expand a search –using AND NOT to restrict a search –understanding filters –using filters with Boolean operators –using metasearch engines

Constructing Complex Searches End