Using Search Tools

Download Report

Transcript Using Search Tools

Using Search Tools
on the Internet
They’re NoT All
The Same!
1
3 Types
The 3 main types of
search tools used to
find information are:
Subject
Directories
Subject Directories
Search Engines
Multiple Search
Engines
Search
Engines
The
Web
Multiple
Search
Engines
2
Subject Directories
Are produced by humans who have reviewed a
web site and allocated a subject to that
particular web site.
The web site’s detail, including it’s address are
then organized under these subjects categories.
Examples:
Yahoo
Excite
Magellan
The Aussie Index
http://www.yahoo.com.au
http://www.excite.com/Subject
http://www.mckinley.com
http://www.aussie.com.au
3
Yahoo
Human selection – not all inclusive
Functions more as a directory
Sparse abstracts (descriptions of web
sites)
Updating is slow
Boolean operators (AND, OR)
Yahooligans (for kids)
Web tutorials (self guided learning)
4
Excite
Limited database
Intelligent searches i.e. related/synonymous
terms: e.g. elderly people, senior citizens
(Concept search)
Content type selection: current news, Excite
Germany
Boolean operators: limited - AND, NOT, OR
5
Magellan
Human selection
Site easy to navigate
Abstracts are actually reviews of entire site
Aims to provide thought provoking, current, in depth
information
Indicator if suitable for kids, (net nanny)
Greenlight sites: no content for mature audiences
Boolean operators: AND, OR, NOT, NEAR, WITH,
ADJACENT
6
Search Engines
Are a little more complicated and are made up of
3 parts;
1. A computer program which visits a web site, reads the
information and picks out key words
2. A very large list of subjects in alphabetical order, (index)
which is created from the key words
3. The search part of the program which looks at your search term
and and then checks your word with the list and reports back to
you.
7
Search Engines
Examples:
Alta Vista
Google
Hotbot
Infoseek
Nine MSN
http://www.altavista.com
http://www.google.com
http://www.hotbot.com
http://www.infoseek.com
http://search.ninemsn.com.au/
8
Alta Vista
Automatic indexing of every word on every page –
high recall/ low relevance.
No selection criteria for sites
Abstract is first 25 words on the first page
Ask Alta Vista a question
Limited use of Boolean operators to refine search –
use of +, -, *, AND, OR, NOT, NEAR
Basic, advanced searches, refine, FAQ’s
9
Google
Is the BIGGEST search engine database in the world http://www.lib.berkeley.edu/TeachingLib/Guides/Internet/Google.html
(Updated 5 Sept, 2002)
AND is always the default between terms
Limited Boolean search terms – OR
Google lets you search full text of most PDF files
(Personal Document Files) on the web
Lots of "stop words" which you have to precede with a +
to search or search in quotes.
Offers Advanced Search
Special features include, Google Image Search, Google
News, Google Special Searches, Google University Search
10
NINEMSN SEARCH
An Australian Search Engine
Results come from Looksmart
Australia and Inktomi
Is linked to ninemsn, which is Australia's
number-one website
Can download their free filter (net
nanny)
11
Multiple Search
Engines
Are able to search using a keyword you type in, across
a number of already existing search engines and
subject directories, therefore a much wider search is
carried out.
They only use the top 10-15 hits from each search
engine. This means they aren’t as good for in-depth
searches.
Examples:
Metacrawler
Dogpile
Savvy Search
http://www.metacrawler.com/index.html
http://dogpile.com
http://www.savvysearch.com/
12
Metacrawler
Can choose to search by “any’, “all” or “phrase”
Queries nine different engines.
Can limit by geographic region and type of site (edu, gov, etc).
Has Basic and Advanced search options
Special search features include: Song and audio file,
Images, Multimedia, Message Boards, News,
Shopping, Search by Country
13
Dogpile
Queries more than 20 databases.
Has Basic and Advanced search options
Special search features include: Directory
Song and audio file, Images, Multimedia, File
Search, Message Boards.
14
The Last Word
Choose the
Search Tool that
best meets your
information
needs!
Power Point by Nicole Slinger
15