1. Web Mining Research: A Survey
Raymond Kosala and Hendrik Blockeel
ACM SIGKDD , July 2000
Presented by Drew DeHaas

2. Outline Introduction Web Mining Web Content Mining
Web Structure Mining
Web Usage Mining
Conclusion & Exam Questions

3. Motivation for Web Mining
World Wide Web is popular/interactive medium for disseminating information
It is also huge, diverse, and dynamic: raising issues of scalability, multimedia data, and temporal information.
Both information users and information providers face problems due to the nature of the web.

4. Problems: Information Users
Finding relevant information
Relevant search results are hard to come by
Inability to index all of the information on web
Creating new knowledge out of available information on the web
Extract knowledge out of collected data
Personalizing the information available
Catering to personal preference in content and presentation

5. Problem: Information Providers
The main problem that information providers face is learning about consumers/users
What does the customer do?
What does the customer want to do?
Personalizing to individual users
Using web data to effectively market products and/or services

6. Other Approaches Web mining is not the only approach Database approach
Information retrieval
Natural language processing
In-depth syntactic and semantic analysis
Web document community
Standards, manually appended meta-information, maintained directories, etc

7. Direct vs Indirect Web Mining
Web mining techniques can be used to solve the information overload problems:
Directly
Attack the problem with web mining techniques
E.g. newsgroup agent classifies news as relevant
Indirectly
Used as part of a bigger application that addresses problems
E.g. used to create index terms for a web search service

8. The Research
Converging research from: Database, information retrieval, and artificial intelligence (specifically NLP and machine learning)
Paper focuses on research from the machine learning point of view

9. Outline Introduction Web Mining Web Content Mining
Web Structure Mining
Web Usage Mining
Conclusion & Exam Questions

10. Web Mining: Definition
“Web mining refers to the overall process of discovering potentially useful and previously unknown information or knowledge from the Web data.”
Can be viewed as four subtasks
Not the same as Information Retrieval
Not the same as Information Extraction

11. Web Mining: Subtasks Resource finding
Retrieving intended documents
Information selection/pre-processing
Select and pre-process specific information from selected documents
Generalization
Discover general patterns within and across web sites
Analysis
Validation and/or interpretation of mined patterns

12. Web Mining: Not IR or IE
Information retrieval (IR) is the automatic retrieval of all relevant documents while at the same time retrieving as few of the non-relevant as possible
Web document classification, which is a Web Mining task, could be part of an IR system (e.g. indexing for a search engine)

13. Web Mining: Not IR or IE
Information extraction (IE) aims to extract the relevant facts from given documents while IR aims to select the relevant documents
IE systems for the general Web are not feasible
Most focus on specific Web sites or content

14. Web Mining and Machine Learning
Web mining not the same as learning from the Web.
Some applications of machine learning on the web are not Web Mining
Some methods used for Web Mining besides machine learning
However, there is a close relationship between web mining and machine learning.

15. Web Mining Categories Web Content Mining Web Structure Mining
Discovering useful information from web contents/data/documents.
Web Structure Mining
Discovering the model underlying link structures on the Web
Web Usage Mining
Try to make sense of data generated by Web surfer’s sessions or behaviors

16. Web Mining: The Agent Paradigm
User Interface Agents
information retrieval agents, information filtering agents, & personal assistant agents.
Distributed Agents
distributed agents for knowledge discovery or data mining.
Problem solving by a group of agents

17. Web Mining: The Agent Paradigm
Content-based approach
The system searches for items that match based on an analysis of the content using the user preferences.
Collaborative approach
The system tries to find users with similar interests
Recommendations given based on what similar users did

18. Outline Introduction Web Mining Web Content Mining
Web Structure Mining
Web Usage Mining
Conclusion & Exam Questions

19. Web Content Mining: Intro
Motivations
Most of the data on the internet is accessible through the Web
Digital libraries are becoming prevalent
Businesses and services are moving “online”
Applications are moving from the “desktop” to the Web

20. Web Content Mining: Intro
Types of data dealt with
Textual, image, audio, video, metadata, hyperlinks
Multimedia mining
Can be an instance of Web Mining
Hidden data
Dynamic or private
Unstructured (free text), semi-structured (HTML, etc), and structured (data in tables, or pages generated from a database)

21. Web Content Mining: IR View
Unstructured Documents
Bag of words, or phrase-based feature representation
Features can be boolean or frequency based
Features can be reduced using different feature selection techniques
Word stemming, combining morphological variations into one feature
Possibly use n-gram representations (encodes some context)

23. Web Content Mining: IR View
Semi-Structured Documents
Uses richer representations for features, based on information from the document structure (typically HTML and hyperlinks)
Uses common data mining methods (whereas unstructured might use more text mining methods)

25. Web Content Mining: DB View
Tries to infer the structure of a Web site or transform a Web site to become a database
Better information management
Better querying on the Web
Can be achieved by:
Finding the schema of Web documents
Building a Web warehouse
Building a Web knowledge base
Building a virtual database

26. Web Content Mining: DB View
Mainly uses the Object Exchange Model (OEM)
Represents semi-structured data (some structure, no rigid schema) by a labeled graph
Process typically starts with manual selection of Web sites for content mining
Main application: building a structural summary of semi-structured data (schema extraction or discovery)

28. Outline Introduction Web Mining Web Content Mining
Web Structure Mining
Web Usage Mining
Conclusion & Exam Questions

29. Web Structure Mining
Interested in the structure between Web documents (not within a document)
Inspired by the study of social networks and citation analysis
Example: PageRank – Google
Application: Discovering micro-communities in the Web
Measuring the “completeness” of a Web site

30. Outline Introduction Web Mining Web Content Mining
Web Structure Mining
Web Usage Mining
Conclusion & Exam Questions

31. Web Usage Mining
Tries to predict user behavior from interaction with the Web
Wide range of data (logs)
Web client data
Proxy server data
Web server data
Two common approaches
Map usage data into relational tables and use adapted data mining techniques
Use log data directly by utilizing special pre-processing techniques

32. Web Usage Mining
Typical problems: Distinguishing among unique users, server sessions, episodes, etc in the presence of caching and proxy servers
Often Usage Mining uses some background or domain knowledge
E.g. site topology, Web content, etc

33. Web Usage Mining Two main categories:
Learning a user profile (personalized)
Web users would be interested in techniques that learn their needs and preferences automatically
Learning user navigation patterns (impersonalized)
Information providers would be interested in techniques that improve the effectiveness of their Web site or biasing the users towards the goals of the site

34. Outline Introduction Web Mining Web Content Mining
Web Structure Mining
Web Usage Mining
Conclusion & Exam Questions

35. Conclusions
Tried to resolve confusion with regards to the term Web Mining
Differentiated from IR and IE
Suggest three Web mining categories:
Content, Structure, and Usage Mining
Briefly described approaches for the three categories
Explored connection with agent paradigm

36. Exam Question #1
Question: Outline the main characteristics of Web information.
Answer: Web information is huge, diverse, and dynamic.

37. Exam Question #2
Question: How data mining techniques can be used in Web information analysis? Give at least two examples.
Classification: classification on server logs using decision tree, Naïve-Bayes classifier to discover the profiles of users belonging to a particular class
Clustering: Clustering can be used to group users exhibiting similar browsing patterns.
Association Analysis: association analysis can be used to relate pages that are most often referenced together in a single server session.

38. Exam Question #1
Question: What are the three main areas of interest for Web mining?
Answer: (1) Web Content
(2) Web Structure
(3) Web Usage

39. Questions?