Lecture 10 - Content-Based Applications

Question 1

What’s a B2B transaction?

Answer 1

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

Question 2

What are the components of a search engine?

Answer 2

Database of references to webpages

A web crawler

An interface

Information retrieval system

Question 3

What are the elements of the search engine database?

Answer 3

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Search engines tend to be out of date

Question 4

What does a web crawler do?

Answer 4

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

Question 5

What does the search engine interface do?

Answer 5

Gathers input from users

Presents results from the IR system

Often presents items in a ranked order

Requires user input

Question 6

What are the two main methods of search term matching?

Answer 6

Keyword Searching and Concept-based searching

Question 7

How does keyword searching work?

Answer 7

Matches single terms, computing cosine

Question 8

How does concept-based searching work

Answer 8

Examining clusters of work

Attempts to determine the meaning of a query

Question 9

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

Answer 9

Boolean Operators

Extended Operators

Stop word deletion

Stemming

Searching in fields (e.g. host)

Question 10

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

Answer 10

Early words more important

Title is important

frequency of occurrence matters for some

infrequent words matter more

modification date

Question 11

How does Google handle searches differently than other SEs?

Answer 11

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

Links as money

Question 12

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

Answer 12

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

Question 13

What does Google’s Indexer do?

Answer 13

Reads repository, uncompresses and parses documents

Converts pages into stats on word occurrences, hits

Includes intfo about the page, font size, capitalization

Question 14

What does google’s sorter do?

Answer 14

Resorts barrels by wordID instead of docID

Question 15

What does dumpLexicon do?

Answer 15

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

Question 16

What is Googlebombing?

Answer 16

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

Question 17

What is the Deep Web?

Answer 17

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

Question 18

How is the invisible web changing over time?

Answer 18

More search engines are parsing non-html content than before

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

Question 19

What is dogpile?

Answer 19

A well known meta-crawler

Question 20

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

Answer 20

Use multiple search engines

Search within results

Use boolean expressions

Question 21

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

Answer 21

Always use ALT attributes

Avoid frames

Links between your pages

Use metadata, formal and informal

Question 22

How do you increase your pages popularity?

Answer 22

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

Question 23

Why is metadata important?

Answer 23

• 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

Question 24

How can we reduce inconsistencies in our metadata?

Answer 24

Clearly label attributes

Stick to formats and rules

Catalogue Rules

Question 25

What is Dublin Core (DC)?

Answer 25

It has 15 core elements

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

Question 26

What does RDF stand for?

Answer 26

Resource Description Framework

Question 27

What does a resource description framework do?

Answer 27

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

Question 28

What are the applications of RDF?

Answer 28

• 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”

Question 29

what are the disadvantages of metadata?

Answer 29

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)

Question 30

What is the short term disadvantage of metadata?

Answer 30

Metadata imposes a load on the server

Question 31

Metadata is becoming important, how should we handle it when creating a site?

Answer 31

Start collecting it immediately

Automate as much as possible

Ensure information providers use metadata