CS 121 Quiz 1 Study Guide With
Complete Solutions
What is information retrieval? - ANSWER The activity of searching and
extracting information from a
collection of information resources.
What was the first best mechanism for advertising on the Web? - ANSWER
Searching
A different definition of information retrieval - ANSWER Information retrieval
is a field concerned with the structure, analysis, organization, storage,
searching, and retrieval of information
Types of IR - ANSWER Search, Filtering or Tracking(detecting documents
of interest), Classification(Labeling documents with pre-existing labels),
Question Answering(Beyond searching for documents, searching for
answers)
Types of Search Engines - ANSWER Web Search, Vertical Search,
Enterprise Search, Desktop Search, Peer-to-Peer Search
Database Engines vs. Search Engines - ANSWER Database:
-Requires data to be well-structured and well-defined
-Typically involves not just text but numbers
-Requires use of formal language and logic
Search:
, -Vague and varied information needs
-Informal and ad-hoc queries
-Requires engine to infer meaning of words and sentences
Retrieval Models - ANSWER -Conceptual designs of what to pay attention
to when
matching a query and a document
Good retrieval model: finds documents relevant to the person who
submitted the query
Web IR - ANSWER The Web is huge (cannot store in any centralized
memory! )
•The Web changes all the time (needs to update constantly! )
•There is information to avoid ( adversarial IR! )
•One interface for hugely divergent needs
Issues with Web Search Engines - ANSWER -Performance
•Response time
•Query throughput
•Indexing speed
-Speed in discovery and integration of new documents
-Coverage
-Freshness
-Spam
Search Engineers - ANSWER •Develop and maintain search engines
•Design or optimize content for search engines
Text Acquisition - ANSWER •Crawler
•Feeds
•Text conversion (e.g. PDF-> text)
•Document Store
Text Transformation - ANSWER •Parser = Tokenizer + Structure
•Stopping : removing words "the", "of", etc.
•Stemming : grouping similar words together (e.g. fishes->fish)
•Link extraction and analysis: how popular is a certain link
•Information Extraction (text structure)
•Classifier (topic, non-content, spam, etc.)
Complete Solutions
What is information retrieval? - ANSWER The activity of searching and
extracting information from a
collection of information resources.
What was the first best mechanism for advertising on the Web? - ANSWER
Searching
A different definition of information retrieval - ANSWER Information retrieval
is a field concerned with the structure, analysis, organization, storage,
searching, and retrieval of information
Types of IR - ANSWER Search, Filtering or Tracking(detecting documents
of interest), Classification(Labeling documents with pre-existing labels),
Question Answering(Beyond searching for documents, searching for
answers)
Types of Search Engines - ANSWER Web Search, Vertical Search,
Enterprise Search, Desktop Search, Peer-to-Peer Search
Database Engines vs. Search Engines - ANSWER Database:
-Requires data to be well-structured and well-defined
-Typically involves not just text but numbers
-Requires use of formal language and logic
Search:
, -Vague and varied information needs
-Informal and ad-hoc queries
-Requires engine to infer meaning of words and sentences
Retrieval Models - ANSWER -Conceptual designs of what to pay attention
to when
matching a query and a document
Good retrieval model: finds documents relevant to the person who
submitted the query
Web IR - ANSWER The Web is huge (cannot store in any centralized
memory! )
•The Web changes all the time (needs to update constantly! )
•There is information to avoid ( adversarial IR! )
•One interface for hugely divergent needs
Issues with Web Search Engines - ANSWER -Performance
•Response time
•Query throughput
•Indexing speed
-Speed in discovery and integration of new documents
-Coverage
-Freshness
-Spam
Search Engineers - ANSWER •Develop and maintain search engines
•Design or optimize content for search engines
Text Acquisition - ANSWER •Crawler
•Feeds
•Text conversion (e.g. PDF-> text)
•Document Store
Text Transformation - ANSWER •Parser = Tokenizer + Structure
•Stopping : removing words "the", "of", etc.
•Stemming : grouping similar words together (e.g. fishes->fish)
•Link extraction and analysis: how popular is a certain link
•Information Extraction (text structure)
•Classifier (topic, non-content, spam, etc.)
