User
Interface
-
Provides
a mechanism for a user to submit queries to the search engine.
-
It
is easy to be used and it uses forms.
-
It
will displays the search results in a convenient way.
-
A
summary of each matched page is shown.
Searcher
-
It
is a program that uses the search engine's database to locate the matches for a specific query.
-
The
database of a search engine holds extremely large indexed pages.
-
A
highly efficient search algorithm is necessary.
-
Computer Scientists have spent years
to develop the searching and sorting methods.
-
There
are a lot of computer references books written.
Evaluator
-
The
searcher returns a set of URLs, that match your query
-
Not
all of the hits equally match your query
-
More
references to the page, the ranking of the page will be higher
-
How
the relevancy Score is calculated?
- The different between
one engine to another one for example yahoo is different from
Alta-vista.
- The number of
times of the word appears?
- The query words
appear in the title?
- The query words
appear in the META tag?
gatherer
- It
is a program that travels in the WEB and gathers information about the WEB documents.
-
It runs at a short and regular intervals.
-
It returns information and will be indexed to the database.
-
Alternate
name : Bot , Crawler, Robot, Spider and Worm.
indexer
-
It
will create a set of keys or an index to organized the data
-
Indexes
need to be rebuilt frequently
-
The
examples of indexer are libraries-- Author, title ISBN and etc...
-
It
is important to ensure that the returned URL is not out of date.
- The
search engine is very complex and needs to break down into different components. when it is
being broken down into different components, the search engine can
function smoother.