a search engine is a web site that collects and organizes content from all over the internet search...
TRANSCRIPT
GROUP MEMBERS
NIDA IRFAN AHSAN AKRAM USMAN BASHIR AMBER SHAHEEN GHULAM HASSAN
SEARCH ENGINE
INTRODUCTION A search engine is a web site that collects and
organizes content from all over the internet
Search engines look through their own databases of information in order to find what it is that you are looking for.
“Search engine” is the popular term for an Information Retrieval (IR) system.
INTRODUCTION
Search engines match queries against an index that they create. The index consists of the words in each document, plus pointers to their locations within the documents. This is called an inverted file.
INTRODUCTIONA search engine or IR system
comprises four essential modules:
A document processorA query processorA search and matching functionA ranking capability
HIST
ORY
Archie -> First search tool for the Internet
Gopher -> Indexed plain text documents
Jughead -> Searched the files stored in Gopher index
Wandex -> First Web search engine systems
HISTORY
Alan Emtage created the first ever search engine called Archie in 1990.
Archie collects information by crawling the internet.
It matches the files it found with search queries and returned results from its database.
ArchieHISTORY
HISTORY It was introduced in 1990 It is the protocol system It allows text files to be hierarchically
organized It is used to enable the simple sharing of
documents with which could be located in any part of the world
Gopher
HISTORY Jughead
It was developed by Rhett Jones in 1993 Jug head is the search engine system for
the gopher protocol It searches the single server at a time It was officially released in 2006
HISTORY Wandex
It was the first search engine introduced in 1993 by Matthew Gray
It was the first search engine that is usable for world wide web
Wandex itself was based on the world wide web wanderer which merely listed websites
Mod
ules
Search Engine Modules A document processor
A query processor
A search and matching function
A ranking capability
The document processor prepares, processes, and inputs the documents, pages, or sites that users search against. The document processor performs some or all of the following steps:
Search Engine Modules Document Processor
Search Engine Modules Normalizes the document stream to a
predefined format. Breaks the document stream into desired
retrievable units. Isolates and metatags subdocument
pieces. Identifies potential index able elements in
documents.
Search Engine Modules Deletes stop words. Stems terms. Extracts index entries. Computes weights. Creates and updates the main
inverted file against which the search engine searches in order to match queries to documents.
Query Processor Query processing has seven possible
steps. System can cut these steps short and
proceed to match the query to the inverted file.
Document processing shares many steps with query processing.
Search Engine Modules
More steps and more documents make the process more expensive for processing
Search system designers must choose what is most important to their users, time or quality.
Publicly available search engines usually choose time over very high quality, having too many documents to search against.
Search Engine Modules
Search Engine Modules
Step 1: TokenizingStep 2: ParsingStep 3: STOPLISTStep 4: StemmingStep 5: Creating the queryStep 6: Query expansionStep 7: Query term weighting
Search Engine Modules Search and matching function
Searching the inverted file for documents meeting the query requirements
It is the simple binary search It follows the simple document
representation, query representation and algorithm
After computing the similarity of each document in the subset of documents, the system presents an ordered list to the user
Type
s
Types of Search Engine Crawler-Based Search
Engines
Human-Powered Directories
Hybrid Search Engines" Or Mixed Results
Wor
king
Working of Search Engine
SpidersRobots
Adva
nta
ges
Advantages of Search Engine
It is easy and quick
It is a quick access to information
Save of time
It help to organize internet and individual websites
Good
Ch
oice
Choice of Search Engine The search system development or selection should be based primarily on the local needs Consider using freeware search engines, if your requirements are met by these. Consider if the web server you are using supports indexing and search, and if this is adequate for you
Choice of Search Engine
The IT Professionals should make an effort to keep themselves abreast of the current web technologies The features available within a tool
should be made use of properly to get maximum benefits
Conc
lusi
on
Search engine plays important role in accessing the content over the internet, it fetches the pages requested by the user.
It made the internet and accessing the information just a click away.
Conclusion
ConclusionThe need for better search engines only
increases
The search engine sites are among the most popular websites.