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Flashcards in Lecture 10 - Content-Based Applications Deck (31)
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What's a B2B transaction?

Business to Business uses the WWW as a distributed document delivery service


What are the components of a search engine?

Database of references to webpages

A web crawler

An interface

Information retrieval system


What are the elements of the search engine database?

Where the users queries are matched

Contains only essential parts of the page

Only includes indexed pages

Search engines tend to be out of date


What does a web crawler do?

Records the data it finds such as words, metadata and alt attributes


What does the search engine interface do?

Gathers input from users

Presents results from the IR system

Often presents items in a ranked order

Requires user input


What are the two main methods of search term matching?

Keyword Searching and Concept-based searching


How does keyword searching work?

Matches single terms, computing cosine


How does concept-based searching work

Examining clusters of work

Attempts to determine the meaning of a query


What are the basic information retrieval features of a search engine?

Boolean Operators

Extended Operators

Stop word deletion


Searching in fields (e.g. host)


What are the rules of ranked output for most search engines?

Early words more important

Title is important

frequency of occurrence matters for some

infrequent words matter more

modification date


How does Google handle searches differently than other SEs?

PageRanktm method is based on popularity, use of keywords and relevance.

Links as money


Google's Anatomy: What does the URL server do?

Sends lists of URLS to be fetched

Fetched pages are sent to the store server

The store server compresses and stores pages into a repository
Each page has a docID


What does Google's Indexer do?

Reads repository, uncompresses and parses documents

Converts pages into stats on word occurrences, hits

Includes intfo about the page, font size, capitalization


What does google's sorter do?

Resorts barrels by wordID instead of docID


What does dumpLexicon do?

Takes the list and lexicon to produce a new lexicon

To be used by the searcher to answer questions

Using the inverted indx, lexicn and PageRanks


What is Googlebombing?

Specifically targeting a web page to rank in 1st position for a particular search query


What is the Deep Web?

Also called the invisible web, it contains documents not indexed by Search Engines.


How is the invisible web changing over time?

More search engines are parsing non-html content than before

Companies are making more content available by keeping urls stable and including sitemaps


What is dogpile?

A well known meta-crawler


As a searcher, what are steps to success in search engines?

Use multiple search engines

Search within results

Use boolean expressions


As a creator, what are the steps to success in search engines?

Always use ALT attributes

Avoid frames

Links between your pages

Use metadata, formal and informal


How do you increase your pages popularity?

Don't use systematic reciprocal linking

Use a context map at the top of each page

Don't use frames

Think through dynamic content implications


Why is metadata important?

-It's useful for describing and locating info

-Judge relevance of information

-Promote good information management

-Search tools and information gateways can use metadata when location and describing resources


How can we reduce inconsistencies in our metadata?

Clearly label attributes

Stick to formats and rules

Catalogue Rules


What is Dublin Core (DC)?

It has 15 core elements

§ Title, Creator, Subject, Description, Publisher,
Contributors, Date, Type, Format, Identifier, Source,
Language, Relation, Coverage and Rights


What does RDF stand for?

Resource Description Framework


What does a resource description framework do?

It aims to provide the infrastructure to exchange metadata on the web.

Allows for mix of metadata schemes

Enables automated processing of web resources

Interoperability between applications that exchange machine-understandable information


What are the applications of RDF?

- Resource discovery - search engines
- Cataloguing - describe content and content relationships
- Describing intellectual property rights
- Intelligent software agents - info sharing
- Content rating
- Privacy preferences/policies
- Collections of pages as a single "document”


what are the disadvantages of metadata?

Stored in separate files

Difficult to convince information providers of its importance

Need for standardised usage and procedures

Not trusted by some search engines (because of keyword spamming)


What is the short term disadvantage of metadata?

Metadata imposes a load on the server