Authoritative Sources in a Hyperlinked Environment

Jon M. Kleinberg

Presented By: Talin Kevorkian

Summer 2010 April 20, 2023 1

Overview• Why Do We Care?• Introduction Information• Objective• Approaches and Observed Results• Related Work• Generalization• Conclusion• Evaluation of Pros and ConsApril 20, 2023 2Authoritative Sources in a Hyperlinked

Environment

Why Do We care?• Complexity of WWW as a Hypertext Corpus

• Nature of the Hyperlinked Environment Structure

• Efficiency (Longer Response Time) and Storage Problems Because of Huge Amount of Results Return to the User

April 20, 2023 3Authoritative Sources in a Hyperlinked Environment

Introduction Information• Query Types

SpecificE.g. ”Does Windows 7 Support Oracle 10g?”Scarcity Problem

Broad-Topic E.g. “Sql Programming Language ” Abundance Problem Authority Notion

Similar-Page E.g. “Similar Pages to Oracle.com”April 20, 2023 4

Authoritative Sources in a Hyperlinked Environment

Introduction Information• Link-Based Model

Encoding latent human judgmentConferred Authority

Creating Balance Between Popularity and Relevance

Relation Between Authority and Hubs

April 20, 2023 5Authoritative Sources in a Hyperlinked Environment

Objective• Presenting the Link-Based Model for the

Conferral Authority

• Exploring Authoritative WWW Sources in the Global Range

April 20, 2023 6Authoritative Sources in a Hyperlinked Environment

Approaches and Observed Results

• Focused Subgraph Algorithm for WWW

• Authorities and Hubs Computation

• Approach for Similar-Page Queries

• Sample Observed Results

April 20, 2023 7Authoritative Sources in a Hyperlinked Environment

Focused Subgraph Algorithm for WWW• Inputs:

Query String σ Text-based Search Engine

• Outputs: Set of Hyperlinked Pages as a Directed Graph G(V,E) Root Set Rσ Sub Set Sσ

Almost Small in size Containing Most of Relevant Pages Covering Most of the Strongest Authorities

• Links Type in G[Sσ] Transverse IntrinsicApril 20, 2023 8Authoritative Sources in a Hyperlinked

Environment

Authorities and Hubs Computation• Solution to the approach of Ordering Pages by

Their In-degree Confusion Between Strong “Authorities” and “Universally Popular“ Pages

• Containing Mutually Reinforcing Relationship ConceptApril 20, 2023 9

Authoritative Sources in a Hyperlinked Environment

Authorities and Hubs Computation• Iterate Algorithm

Input: Set of n linked pages Gσ

Outputs: Updated Authority Weight (thru operation I) Updated Hub Weight (thru Operation O)

• Filter Algorithm Input:

Set of n linked pages Gσ Outputs:

Reporting Pages with Top c Authorities Reporting Pages with Top c Hubs April 20, 2023 10Authoritative Sources in a Hyperlinked

Environment

Approach for Similar-Page Queries

• First Step: What Do Users of the WWW Decide to be Related to a Page When They Create any Pages and Hyperlinks

• Second Step: Applying Link Structure to the Concept of “Similarity”

• Third Step: Using concept of Authorities and Hubs

April 20, 2023 11Authoritative Sources in a Hyperlinked Environment

Sample Observed Results(For Broad-Specific Queries)

Query String Authorities Description

“Search Engine” .346 http://www.yahoo.com/.291 http://www.excite.com/.239 http://www.mckinley.com/.231 http://www.lycos.com/.231 http://www.altavista.digital.com/

Yahoo!ExciteWelcome to Magellan!Lycos Home PageAltaVista: Main Page

“Gates” .643 http://www.roadahead.com/ Bill.458 http://www.microsoft.com/.440 http://www.microsoft.com/corpinfo/bill-g.htm

Gates: The Road AheadWelcome to Microsoft

April 20, 2023 12Authoritative Sources in a Hyperlinked Environment

Sample Observed Results (For Similar-Pages Queries)

Query String Authorities Description

“www.honda.com” .202 http://www.toyota.com/.199 http://www.honda.com/.192 http://www.ford.com/.173 http://www.bmwusa.com/.162 http://www.volvocars.com/.158 http://www.saturncars.com/

.155 http://www.nissanmotors.com/

.145 http://www.audi.com/

.139 http://www.4adodge.com/

.136 http://www.chryslercars.com/

Welcome to @ToyotaHondaFord Motor CompanyBMW of North America, Inc.VOLVOWelcome to the Saturn Web SiteNISSAN - ENJOY THE RIDEAudi Homepage1997 Dodge SiteWelcome to Chrysler

April 20, 2023 13Authoritative Sources in a Hyperlinked Environment

Related Work

Link Structure is Related to:

• Definition of Standing, Impact and Influence Concepts

• WWW Ranking Techniques

• Data Clustering

April 20, 2023 14Authoritative Sources in a Hyperlinked Environment

Standing, Impact and Influence Concepts

• Social Network Proposed Standing Measure

Katz Theory: Based on Path-Counting Hubbell Theory : Based on Nodes Weight-Propagation

• Scientific Citations Proposed Impact/Influence Measure Garfield’s Impact Theory Pinski-Narin Influence TheoryApril 20, 2023 15Authoritative Sources in a Hyperlinked

Environment

WWW

Ranking

Techniques

• Ranking Measure Proposal:

Botafogo-Rivlin-Shniderman Theory

Carriere-Kanzman Theory

Brin-Page Theory and Contrast with This Paper Approach

April 20, 2023 16Authoritative Sources in a Hyperlinked Environment

Data Clustering• Clustering needs :

Similarity Functions Bibliographic Coupling Co-Citation

Cluster Producer Functions Small-Griffith Approach Dimension-Reduction Spectral Graph partitioning Centroid Scaling

April 20, 2023 17Authoritative Sources in a Hyperlinked Environment

Generalization• Specific Queries

Diffusion Concept• Set of Hubs and Authorities can be Separated

from each other Because: Query String has different Meaning like “Jaguar” Query String is a Highly Polarized Subject Like

“Abortion” Query String can be Applied in Multiple Communities

like “Randomized Algorithms”April 20, 2023 18Authoritative Sources in a Hyperlinked

Environment

GeneraliztionSample Results

Query String Authorities Description

“Jaguar” 2nd non-principal vector, positive end.255 http://www.jaguarsnfl.com/

.137 http://www.nando.net/SportServer/football/nfl/jax.html

3rd non-principal vector, positive end.227 http://www.jaguarvehicles.com/

.227 http://www.collection.co.uk/

Official Jacksonville Jaguars NFL Website

Jacksonville Jaguars Home Page

Jaguar Cars Global Home Page

The Jaguar Collection

April 20, 2023 19Authoritative Sources in a Hyperlinked Environment

Conclusion• Basic Elements of Paper Approach

Applying Notation of Authoritative Sources Selecting High Quality of Results Dealing with Scale Problem Exploring Structure of Hubs and Authorities

April 20, 2023 20Authoritative Sources in a Hyperlinked Environment

Evaluation of Pros and Cons• Pros:

Clearly Describe the Algorithms and Applied Approaches

Provide Tangible Examples and Results Enough Connection to Related Works

• Cons: Ignoring the Textual Contents of pages Complexity in the Nature of Quality Judgment Concentrating mostly on Broad-Topic Queries

April 20, 2023 21Authoritative Sources in a Hyperlinked Environment

Q & A

April 20, 2023 22Authoritative Sources in a Hyperlinked Environment