Week 7: Web Searching

Web Searching: An act of looking for information in computer databases or network.

Web Searching Categories:

(i) Directories
-web guide (hierarchical representation of hyperlinks)
-enormous collection links to sites, arranged in different categories
-top level = wide range of very general topics
-each topic contains hyperlinks of more specialized subtopic

(ii) Search Engines
-computer program that allows users to submit query that consists of word or phrase and searches databases

(iii) Meta-search Engines
-use of more than one other search engine to complete the search
-the results are ranked according to how well they match with the query
-Advantage : a single query can access lot of search engines
-Disadvantage : a lot of matches will not be suitable for you

(iv) Yellow Pages
-allows users to lookup information about individuals
-to track down telephone numbers, email addresses
-contain certain information about businesses

Web Browser: software application used to locate and display web


Searching Techniques:

(i) Pattern Matching Queries (Fuzzy Query)
- can enter ''ungrammatical sentence'', ''incomplete sentence fragments''. ''nonsence words''
- search engines gets collection of keywords
- required keyword "+"
- prohibited keyword "-"

(ii) Boolean Queries
- query that consists keywords but with logical operators (AND, OR, NOT)
-X AND Y - will returns URLs that  contain both X and Y
-X OR Y - will returns URLs that contain either X or Y
-X AND NOT Y - will returns URLs that contain X and do not contains Y

Searching Strategy

• User Interface- Allows you to type a query and displays the results.
• Searcher-  The engine searches the database for matching your query.
• Evaluator- The engine assigns scores to the retrieved information.
• Gatherer- The component that travels the WEB, and collects information.
• Indexer- The engine that categorizes the data collected by the gatherer.

Web Resources Evaluation