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.