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Investigating the Change of Web Pages’ Titles Over Time

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    Investigating the Change of Web Pages’ Titles Over Time - Presentation Transcript

    1. Investigating the Change of Web Pages’ Titles Over Time Martin Klein and Michael L. Nelson Old Dominion University {mklein,mln}@cs.odu.edu InDP 2009 Austin, TX 06/19/2009
    2. The Problem 2
    3. The Problem http://www.pspcentral.org/events/annual_meeting_2003.html 2
    4. The Problem http://www.pspcentral.org/events/annual_meeting_2003.html 2
    5. The Problem http://www.pspcentral.org/events/annual_meeting_2003.html 2
    6. The Problem http://www.pspcentral.org/events/annual_meeting_2003.html 2
    7. The Environment Web Infrastructure (WI) [McCown07] • Web search engines (Google, Yahoo!, MSN Live) and their caches • Research projects (CiteSeer) • Web archives (Internet Archive) [McCown07] - F. McCown “Lazy Preservation: Reconstructing Websites from the Web Infrastructure”, PhD thesis, Old Dominion University, 2007. 3
    8. The Bigger Picture (1) DONE query for URL in: ·search engine caches present ! (2) ·Internet Archive results user is satisfied (3) ! ·identify dissimilar pages ·extract titles ·generate LSs ·obtain tags no results ·query search engines present found results ! user is ! (4) DONE satisfied (5) ·include link neighborhood ·relevance feedback ·user interaction: ! request keywords ! change number of terms in LS ! add/delete term from LS ! advanced search operators (6) present results ! DONE 4
    9. The Bigger Picture (1) • System catches DONE 404 “Page not found” errors query for URL in: ·search engine caches present ! (2) ·Internet Archive results user is satisfied (3) ! ·identify dissimilar pages ·extract titles ·generate LSs ·obtain tags no results ·query search engines present found results ! user is ! (4) DONE satisfied (5) ·include link neighborhood ·relevance feedback ·user interaction: ! request keywords ! change number of terms in LS ! add/delete term from LS ! advanced search operators (6) present results ! DONE 4
    10. The Bigger Picture (1) • System catches DONE 404 “Page not found” errors ! • query for URL in: (2) ·search engine caches ·Internet Archive present results user is Discovers copy of missing page in WI and provides to user satisfied (3) ! ·identify dissimilar pages ·extract titles ·generate LSs ·obtain tags no results ·query search engines present found results ! user is ! (4) DONE satisfied (5) ·include link neighborhood ·relevance feedback ·user interaction: ! request keywords ! change number of terms in LS ! add/delete term from LS ! advanced search operators (6) present results ! DONE 4
    11. The Bigger Picture (1) • System catches DONE 404 “Page not found” errors ! • query for URL in: (2) ·search engine caches ·Internet Archive present results user is Discovers copy of missing page in WI and provides to user satisfied (3) ! ·identify dissimilar pages ·extract titles ·generate LSs • Obtains further data about missing page (LS, title, tags) and ·obtain tags no results ·query search engines present found feeds that back into WI results ! user is ! (4) DONE satisfied (5) ·include link neighborhood ·relevance feedback ·user interaction: ! request keywords ! change number of terms in LS ! add/delete term from LS ! advanced search operators (6) present results ! DONE 4
    12. The Bigger Picture (1) • System catches DONE 404 “Page not found” errors ! • query for URL in: (2) ·search engine caches ·Internet Archive present results user is Discovers copy of missing page in WI and provides to user satisfied (3) ! ·identify dissimilar pages ·extract titles ·generate LSs • Obtains further data about missing page (LS, title, tags) and ·obtain tags no results ·query search engines present found feeds that back into WI results ! • ! user is (4) Provides page at its new location DONE satisfied (5) ·include link neighborhood or “good enough” alternative ·relevance feedback ·user interaction: ! request keywords page ! change number of terms in LS ! add/delete term from LS ! advanced search operators (6) present results ! DONE 4
    13. The Bigger Picture (1) • System catches DONE 404 “Page not found” errors ! • query for URL in: (2) ·search engine caches ·Internet Archive present results user is Discovers copy of missing page in WI and provides to user satisfied (3) ! ·identify dissimilar pages ·extract titles ·generate LSs • Obtains further data about missing page (LS, title, tags) and ·obtain tags no results ·query search engines present found feeds that back into WI results ! • ! user is (4) Provides page at its new location DONE satisfied (5) ·include link neighborhood or “good enough” alternative ·relevance feedback ·user interaction: ! request keywords page • ! change number of terms in LS More sophisticated methods ! add/delete term from LS ! advanced search operators (6) present results ! DONE needed if unsuccessful so far 4
    14. The Bigger Picture (1) DONE query for URL in: ·search engine caches present ! (2) ·Internet Archive results user is satisfied (3) ! ·identify dissimilar pages ·extract titles ·generate LSs ·obtain tags no results ·query search engines present found results ! user is ! (4) DONE satisfied (5) ·include link neighborhood ·relevance feedback ·user interaction: ! request keywords ! change number of terms in LS ! add/delete term from LS ! advanced search operators (6) present results ! DONE 4
    15. The Bigger Picture (1) DONE query for URL in: ·search engine caches present ! (2) ·Internet Archive results user is satisfied (3) ! REAL TIME!!! ·identify dissimilar pages ·extract titles ·generate LSs ·obtain tags no results ·query search engines present found results ! user is ! (4) DONE satisfied (5) ·include link neighborhood ·relevance feedback ·user interaction: ! request keywords ! change number of terms in LS ! add/delete term from LS ! advanced search operators (6) present results ! DONE 4
    16. Search Engine Queries • Lexical signatures (LSs) • Small set of terms capturing the “aboutness” of a document • Generated following the TF-IDF scheme • Phelps and Wilensky assumed ‘5’[Phelps00] • We have shown that 5- and 7-term LSs perform best [Klein08] [Phelps00] - T. A. Phelps and R. Wilensky “Robust Hyperlinks Cost Just Five Words Each”, Technical Report 2000 5 [Klein08] - M.Klein and M.L.Nelson ”Revisiting Lexical Signatures to (Re-)Discover Web Pages”, ECDL 2008
    17. Search Engine Queries • Lexical signatures (LSs) • Small set of terms capturing the “aboutness” of a document • Generated following the TF-IDF scheme • Phelps and Wilensky assumed ‘5’[Phelps00] • We have shown that 5- and 7-term LSs perform best [Klein08] BUT: [Phelps00] - T. A. Phelps and R. Wilensky “Robust Hyperlinks Cost Just Five Words Each”, Technical Report 2000 5 [Klein08] - M.Klein and M.L.Nelson ”Revisiting Lexical Signatures to (Re-)Discover Web Pages”, ECDL 2008
    18. Search Engine Queries • Lexical signatures (LSs) • Small set of terms capturing the “aboutness” of a document • Generated following the TF-IDF scheme • Phelps and Wilensky assumed ‘5’[Phelps00] • We have shown that 5- and 7-term LSs perform best [Klein08] BUT: • IDF can only be estimated when the entire web is the corpus [Phelps00] - T. A. Phelps and R. Wilensky “Robust Hyperlinks Cost Just Five Words Each”, Technical Report 2000 5 [Klein08] - M.Klein and M.L.Nelson ”Revisiting Lexical Signatures to (Re-)Discover Web Pages”, ECDL 2008
    19. Search Engine Queries • Lexical signatures (LSs) • Small set of terms capturing the “aboutness” of a document • Generated following the TF-IDF scheme • Phelps and Wilensky assumed ‘5’[Phelps00] • We have shown that 5- and 7-term LSs perform best [Klein08] BUT: • IDF can only be estimated when the entire web is the corpus • Expensive to generate [Phelps00] - T. A. Phelps and R. Wilensky “Robust Hyperlinks Cost Just Five Words Each”, Technical Report 2000 5 [Klein08] - M.Klein and M.L.Nelson ”Revisiting Lexical Signatures to (Re-)Discover Web Pages”, ECDL 2008
    20. Search Engine Queries • Lexical signatures (LSs) • Small set of terms capturing the “aboutness” of a document • Generated following the TF-IDF scheme • Phelps and Wilensky assumed ‘5’[Phelps00] • We have shown that 5- and 7-term LSs perform best [Klein08] BUT: • IDF can only be estimated when the entire web is the corpus • Expensive to generate Web pages’ titles [Phelps00] - T. A. Phelps and R. Wilensky “Robust Hyperlinks Cost Just Five Words Each”, Technical Report 2000 5 [Klein08] - M.Klein and M.L.Nelson ”Revisiting Lexical Signatures to (Re-)Discover Web Pages”, ECDL 2008
    21. Web Pages’ Titles • Easier/cheaper to obtain than LSs • High availability (1-2% of web pages have no title) • Also capturing “aboutness” of a web page 6
    22. Web Pages’ Titles • Easier/cheaper to obtain than LSs • High availability (1-2% of web pages have no title) • Also capturing “aboutness” of a web page • We have shown that LSs decay over time and their retrieval performance decreases [Klein08] 6
    23. Web Pages’ Titles • Easier/cheaper to obtain than LSs • High availability (1-2% of web pages have no title) • Also capturing “aboutness” of a web page • We have shown that LSs decay over time and their retrieval performance decreases [Klein08] • Investigate change of titles over time 6
    24. Web Pages’ Titles • Easier/cheaper to obtain than LSs • High availability (1-2% of web pages have no title) • Also capturing “aboutness” of a web page • We have shown that LSs decay over time and their retrieval performance decreases [Klein08] • Investigate change of titles over time • General frequency of change 6
    25. Web Pages’ Titles • Easier/cheaper to obtain than LSs • High availability (1-2% of web pages have no title) • Also capturing “aboutness” of a web page • We have shown that LSs decay over time and their retrieval performance decreases [Klein08] • Investigate change of titles over time • General frequency of change • Degree of change as Levenshtein score 6
    26. Dataset • 6k URLs randomly sampled from DMOZ • Parsed the pages and extracted up to three URLs referencing to in-domain pages • Applied filter for: • Inaccessible pages • Pages not containing any links • Pages not in the .com, .net, .org or .edu domain • Pages without copies in the IA 7
    27. Dataset • 6k URLs randomly sampled from DMOZ • Parsed the pages and extracted up to three URLs referencing to in-domain pages • Applied filter for: • Inaccessible pages • Pages not containing any links • Pages not in the .com, .net, .org or .edu domain • Pages without copies in the IA 1090 URLs and more than 100K observations 7
    28. Dataset Length = 1 Length = 2 foo.bar/ foo.bar/bar/ foo.bar/index.html foo.bar/bar/index.html 8
    29. Dataset Length = 1 Length = 2 foo.bar/ foo.bar/bar/ foo.bar/index.html foo.bar/bar/index.html 8
    30. Dataset Length = 1 Length = 2 foo.bar/ foo.bar/bar/ foo.bar/index.html foo.bar/bar/index.html 8
    31. Dataset Length = 1 Length = 2 foo.bar/ foo.bar/bar/ foo.bar/index.html foo.bar/bar/index.html 8
    32. Frequency of Change Number of Changes and Observations in the IA ordered in Number of Changes increasing order by: Number of Observations 10000 1) observations 2) changes Number of Changes/Observations 1000 100 10 1 0 200 400 600 800 1000 URLs 9
    33. Frequency of Change Number of Changes and Observations in the IA ordered in Number of Changes increasing order by: Number of Observations • generally low number of 10000 1) observations 2) changes change Number of Changes/Observations 1000 100 10 1 0 200 400 600 800 1000 URLs 9
    34. Frequency of Change Number of Changes and Observations in the IA ordered in Number of Changes increasing order by: Number of Observations • generally low number of 10000 1) observations 2) changes change • max changes: 25 Number of Changes/Observations 1000 100 10 1 0 200 400 600 800 1000 URLs 9
    35. Frequency of Change Number of Changes and Observations in the IA ordered in Number of Changes increasing order by: Number of Observations • generally low number of 10000 1) observations 2) changes change • max changes: 25 Number of Changes/Observations 1000 • number of observations does not impact the 100 number of changes 10 1 0 200 400 600 800 1000 URLs 9
    36. Times of Change Mean Time Delta Between Changes Time Span Between First and Last Observation in the IA Changes Observations 10000 10000 Mean Time Delta Time Span ●●● ● ●● ● ●● ● ● ●● ● ●● ● ● ●● ●● ● ● ● ● ● ● ● ●●● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ●● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ●●●● ● ● ● ● ●● ●● ● ● ●● ●● ●● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ●● ●● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ●● ● ●●●●● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ●● ● ● ●● ● ● ● ●●● ● ●● ●● ●● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● Number of Changes/Observations ● ● ● ● ● ● ● ● ●●● ● ● ● ● ●● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● 1000 1000 ● ● ● ● ● ● ●● ●● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●●●● ● ● ● ● ●● ● ● ● ●● ●● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ●● ● ●●● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●●● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ●● ● ● ● ● ●● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ●● ● ● ● ● ● ● ●●●● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● Days ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ● ● ● ●● 100 100 ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ●● ●● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ●● ● ●● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●●● ● ● ● ● ●● ● ● ● ● ●● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●●● ● ● ●● ● ●● ● ● ● ● ● ● ● ●● ● ●●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ●●●● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ●●● ●● ● ● ● ● ●● ● ● ● ●● ● ● ● ●● ● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●●● ● ● ● ● ●● ● ●● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●●● ● ● ●● ●● ● ● ●●● ● ●● ● ● ● ●● ● ● ●●● ● ● ● ●● ● ● ● ● ● ●● ● ●● ● ●● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ● ● ●● ● ●● ●● ●●● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ●● ● ● ●●● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ●● ● ● ● ●● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ●● ● ● ● ● ●● ●●● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ●● ● ● ●● ● ●●●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ●●● ● ● ● ● ● ● ● ● ● ● 10 10 ● ●● ● ● ●● ● ● ● ● ●● ●● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ●●● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ●● ● ●● ● ● ●● ●● ● ●● ● ● ● ● ●● ●● ● ● ●● ●● ●● ●● ● ● 1 1 ●●● ●●● 0 200 400 600 800 1000 URLs 10
    37. Times of Change Mean Time Delta Between Changes Time Span Between First and Last Observation in the IA Changes • time span between Observations 10000 10000 Mean Time Delta Time Span ● ●● ● ●● ●● ● ● observation decreases with increasing number ●● ● ● ● ● ● ● ●●● ● ● ● ●●● ● ●● ● ● ●● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ●● ●● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ●●●● ● ● ● ● ●● ●● ● ● ●● ●● ●● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ●● ●● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ●● ● ●●●●● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ●● ● ● ●● ● ● ● ●●● ● ●● ●● ●● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● Number of Changes/Observations ● ● ● ● ● ● ● ● ●●● ● ● ● ● ●● ●● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● of observations ● ● ● ● ● ● ● ● ● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● 1000 1000 ● ● ● ● ● ● ●● ●● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●●●● ● ● ● ● ●● ● ● ● ●● ●● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ●● ● ●●● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●●● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ●● ● ● ● ● ●● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ●● ● ● ● ● ● ● ●●●● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● Days ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ● ● ● ●● 100 100 ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ●● ●● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ●● ● ●● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●●● ● ● ● ● ●● ● ● ● ● ●● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●●● ● ● ●● ● ●● ● ● ● ● ● ● ● ●● ● ●●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ●●●● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ●●● ●● ● ● ● ● ●● ● ● ● ●● ● ● ● ●● ● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●●● ● ● ● ● ●● ● ●● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●●● ● ● ●● ●● ● ● ●●● ● ●● ● ● ● ●● ● ● ●●● ● ● ● ●● ● ● ● ● ● ●● ● ●● ● ●● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ● ● ●● ● ●● ●● ●●● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ●● ● ● ●●● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ●● ● ● ● ●● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ●● ● ● ● ● ●● ●●● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ●● ● ● ●● ● ●●●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ●●● ● ● ● ● ● ● ● ● ● ● 10 10 ● ●● ● ● ●● ● ● ● ● ●● ●● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ●●● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ●● ● ●● ● ● ●● ●● ● ●● ● ● ● ● ●● ●● ● ● ●● ●● ●● ●● ● ● 1 1 ●●● ●●● 0 200 400 600 800 1000 URLs 10
    38. Times of Change Mean Time Delta Between Changes Time Span Between First and Last Observation in the IA Changes • time span between Observations 10000 10000 Mean Time Delta Time Span ● ●● ● ●● ●● ● ● observation decreases with increasing number ●● ● ● ● ● ● ● ●●● ● ● ● ●●● ● ●● ● ● ●● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ●● ●● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ●●●● ● ● ● ● ●● ●● ● ● ●● ●● ●● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ●● ●● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ●● ● ●●●●● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ●● ● ● ●● ● ● ● ●●● ● ●● ●● ●● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● Number of Changes/Observations ● ● ● ● ● ● ● ● ●●● ● ● ● ● ●● ●● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● of observations ● ● ● ● ● ● ● ● ● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● 1000 1000 ● ● ● ● ● ● ●● ●● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●●●● ● ● ● ● ●● ● ● ● ●● ●● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ●● ● ●●● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●●● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● • overall time span just ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ●● ●● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ●● ● ● ● ● ● ● ●●●● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● slightly increases ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● Days ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ● ● ● ●● 100 100 ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ●● ●● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ●● ● ●● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●●● ● ● ● ● ●● ● ● ● ● ●● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●●● ● ● ●● ● ●● ● ● ● ● ● ● ● ●● ● ●●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ●●●● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ●●● ●● ● ● ● ● ●● ● ● ● ●● ● ● ● ●● ● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●●● ● ● ● ● ●● ● ●● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●●● ● ● ●● ●● ● ● ●●● ● ●● ● ● ● ●● ● ● ●●● ● ● ● ●● ● ● ● ● ● ●● ● ●● ● ●● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ● ● ●● ● ●● ●● ●●● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ●● ● ● ●●● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ●● ● ● ● ●● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ●● ● ● ● ● ●● ●●● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ●● ● ● ●● ● ●●●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ●●● ● ● ● ● ● ● ● ● ● ● 10 10 ● ●● ● ● ●● ● ● ● ● ●● ●● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ●●● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ●● ● ●● ● ● ●● ●● ● ●● ● ● ● ● ●● ●● ● ● ●● ●● ●● ●● ● ● 1 1 ●●● ●●● 0 200 400 600 800 1000 URLs 10
    39. Times of Change Mean Time Delta Between Changes Time Span Between First and Last Observation in the IA Changes • time span between Observations 10000 10000 Mean Time Delta Time Span ● ●● ● ●● ●● ● ● observation decreases with increasing number ●● ● ● ● ● ● ● ●●● ● ● ● ●●● ● ●● ● ● ●● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ●● ●● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ●●●● ● ● ● ● ●● ●● ● ● ●● ●● ●● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ●● ●● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ●● ● ●●●●● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ●● ● ● ●● ● ● ● ●●● ● ●● ●● ●● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● Number of Changes/Observations ● ● ● ● ● ● ● ● ●●● ● ● ● ● ●● ●● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● of observations ● ● ● ● ● ● ● ● ● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● 1000 1000 ● ● ● ● ● ● ●● ●● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●●●● ● ● ● ● ●● ● ● ● ●● ●● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ●● ● ●●● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●●● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● • overall time span just ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ●● ●● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ●● ● ● ● ● ● ● ●●●● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● slightly increases ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● Days ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ● ● ● ●● 100 100 ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ●● ●● ● ●● ● ● ● ● ● ●● ● ● ● ● ●● • URLs with many ● ●● ● ●● ● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ●● ● ●● ● ●● ● ● ● ● ● ● ●●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●●● ● ● ●● ● ●● ● ● ● ● ● ● ● ●● ● ●●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ●●●● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ●●● ●● ● ● ● ● ●● ● ● ● ●● ● ● ● ●● ● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●●● ● ● ● ● ●● ● ●● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●●● ● ● ●● ●● ● ● ●●● ● ●● ● ● ● ●● ● ● ●●● ● ● ● ●● ● ● ● ● ● ●● ● ●● ● ●● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ● ● ●● ● ●● ●● ●●● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ●● ● ● observations are being ●●● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ●● ● ● ● ●● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ●● ● ● ● ● ●● ●●● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ●● crawled frequently in a ● ● ●● ● ●●●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ●●● ● ● ● ● ● ● ● ● ● ● 10 10 ● ●● ● ● ●● ● ● ● ● ●● ●● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● short period of time ● ● ●● ● ●●● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ●● ● ●● ● ● ●● ●● ● ●● ● ● ● ● ●● ●● ● ● ●● ●● ●● ●● ● ● 1 1 ●●● ●●● 0 200 400 600 800 1000 URLs 10
    40. Degree of Change Levenshtein Score measured in two different ways O_1 O_1 O_2 O_2 O_3 O_3 O_4 O_4 O_5 O_5 Sliding Rooted 11
    41. Degree of Change Mean Scores of all Titles - Sliding 1 ●●●● ●●● ● ● ●●● ●●●●●●●● ● ●●● ● ● ● ●● ● ● ●●● ●●● ● ●●●●●●● ●● ●●●●●●●●●● ●●●● ●● ●● ● ●● ● ● ●●● ●●●● ● ●● ● ●●●●● ●●●● ●● ●● ●● ● ● ●●●●● ●● ●●● ●●● ● ● ●● ● ● ● ●● ●● ●●● ● ● ● ● ●●●●● ● ●● ●● ●●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ●● ● ●● ●● ● ●● ●● ● ●● ● ●● ● ●●● ●● ● ● ● ●● ● ● ● ● ●● ●● ●● ● ● ● ●● ● ● ● ●● ● ● ● ●● ● ●● ● ● ●●● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ●● ● ●● ● ● ● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ●● ●● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ●●● ● ● ●● ●● ● ● ●●● ●●● ● ● ● ● ●●●● ● ●● ●● ● ●● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ●●● ● ● ● ●● ●● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ●●● ● ● ● ●●● ●●●● ● ● ● ●●●● ● ●● ●● ● ● ●● ● ● ● ● ● ●● ● ●● ● ● ●●● ● ●● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ●●● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ●● ● ●● ● ● ●● ● ● ● ● ● ● ● ●●●● ● ● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●●● ●● ● ●● ●● ● ● ●●● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ●● ● ● ●● ● ● ● ●●● ● ● ● ●● ● ● ● ● ●● ● ●● ● ● ● ● ●● ● ● ● ● ●● ● ●● ● ● ● ● ● ●● ● ● ● ● ●●●● ● ● ●● ● ● ● ●● ● ● ●● ●●● ● ●● ●● ● ● ● ● ● ● ●●●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ●● ● ●● ●● ● ● ● ●● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ●●● ● ● ● ●● ●● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● 0.8 ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● Mean Score ● ● ● ● ● ● 0.6 ● ● ● ● ● ● ● ● ●● ● ● ● 0.4 ● 0.2 0 ● ● ●● ● 0 200 400 600 800 1000 URLs 12
    42. Degree of Change Mean Scores of all Titles - Sliding 1 ●●●● ●●● ● ● ●●● ●●●●●●●● ● ●●● ● ● ● ●● ● ● ●●● ●●● ● ●●●●●●● ●● ●●●●●●●●●● ●●●● ●● ●● ● ●● ● ● ●●● ●●●● ● ●● ● ●●●●● ●●●● ●● ●● ●● ● ● ●●●●● ●● ●●● ●●● ● ● ●● ● ● ● ●● ●● ●●● ● ● ● ● ●●●●● ● ●● ●● ●●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ●● ● ●● ●● ● ●● ●● ● ●● ● ●● ● ●●● ●● ● ● ● ●● ● ● ● ● ●● ●● ●● ● ● ● ●● ● ● ● ●● ● ● ● ●● ● ●● ● ● ●●● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ●● ● ●● ● ● ● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ●● ●● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ●●● ● ● ●● ●● ● ● ●●● ●●● ● ● ● ● ●●●● ● ●● ●● ● ●● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ●●● ● ● ● ●● ●● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ●●● ● ● ● ●●● ●●●● ● ● ● ●●●● ● ●● ●● ● ● ●● ● ● ● ● ● ●● ● ●● ● ● ●●● ● ●● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ●●● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ●● ● ●● ● ● ●● ● ● ● ● ● ● ● ●●●● ● ● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●●● ●● ● ●● ●● ● ● ●●● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ●● ● ● ●● ● ● ● ●●● ● ● ● ●● ● ● ● ● ●● ● ●● ● ● ● ● ●● ● ● ● ● ●● ● ●● ● ● ● ● ● ●● ● ● ● ● ●●●● ● ● ●● ● ● ● ●● ● ● ●● ●●● ● ●● ●● ● ● ● ● ● ● ●●●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ●● ● ●● ●● ● ● ● ●● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ●●● ● ● ● ●● ●● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● • 5 URLs with score = 0 ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● 0.8 ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● Mean Score ● ● ● ● ● ● 0.6 ● ● ● ● ● ● ● ● ●● ● ● ● 0.4 ● 0.2 0 ● ● ●● ● 0 200 400 600 800 1000 URLs 12
    43. Degree of Change Mean Scores of all Titles - Sliding 1 ●●●● ●●● ● ● ●●● ●●●●●●●● ● ●●● ● ● ● ●● ● ● ●●● ●●● ● ●●●●●●● ●● ●●●●●●●●●● ●●●● ●● ●● ● ●● ● ● ●●● ●●●● ● ●● ● ●●●●● ●●●● ●● ●● ●● ● ● ●●●●● ●● ●●● ●●● ● ● ●● ● ● ● ●● ●● ●●● ● ● ● ● ●●●●● ● ●● ●● ●●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ●● ● ●● ●● ● ●● ●● ● ●● ● ●● ● ●●● ●● ● ● ● ●● ● ● ● ● ●● ●● ●● ● ● ● ●● ● ● ● ●● ● ● ● ●● ● ●● ● ● ●●● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ●● ● ●● ● ● ● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ●● ●● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ●●● ● ● ●● ●● ● ● ●●● ●●● ● ● ● ● ●●●● ● ●● ●● ● ●● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ●●● ● ● ● ●● ●● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ●●● ● ● ● ●●● ●●●● ● ● ● ●●●● ● ●● ●● ● ● ●● ● ● ● ● ● ●● ● ●● ● ● ●●● ● ●● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ●●● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ●● ● ●● ● ● ●● ● ● ● ● ● ● ● ●●●● ● ● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●●● ●● ● ●● ●● ● ● ●●● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ●● ● ● ●● ● ● ● ●●● ● ● ● ●● ● ● ● ● ●● ● ●● ● ● ● ● ●● ● ● ● ● ●● ● ●● ● ● ● ● ● ●● ● ● ● ● ●●●● ● ● ●● ● ● ● ●● ● ● ●● ●●● ● ●● ●● ● ● ● ● ● ● ●●●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ●● ● ●● ●● ● ● ● ●● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ●●● ● ● ● ●● ●● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● • 5 URLs with score = 0 ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● 0.8 ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● • 85% of URLs with score ● ● ● ● ● ● ● ● ● ● ● ● ●● ● Mean Score ● ● ● ● ● ● 0.6 >=0.8 ● ● ● ● ● ● ● ● ●● ● ● ● 0.4 ● 0.2 0 ● ● ●● ● 0 200 400 600 800 1000 URLs 12
    44. Degree of Change Mean Scores of all Titles - Sliding 1 ●●●● ●●● ● ● ●●● ●●●●●●●● ● ●●● ● ● ● ●● ● ● ●●● ●●● ● ●●●●●●● ●● ●●●●●●●●●● ●●●● ●● ●● ● ●● ● ● ●●● ●●●● ● ●● ● ●●●●● ●●●● ●● ●● ●● ● ● ●●●●● ●● ●●● ●●● ● ● ●● ● ● ● ●● ●● ●●● ● ● ● ● ●●●●● ● ●● ●● ●●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ●● ● ●● ●● ● ●● ●● ● ●● ● ●● ● ●●● ●● ● ● ● ●● ● ● ● ● ●● ●● ●● ● ● ● ●● ● ● ● ●● ● ● ● ●● ● ●● ● ● ●●● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ●● ● ●● ● ● ● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ●● ●● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ●●● ● ● ●● ●● ● ● ●●● ●●● ● ● ● ● ●●●● ● ●● ●● ● ●● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ●●● ● ● ● ●● ●● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ●●● ● ● ● ●●● ●●●● ● ● ● ●●●● ● ●● ●● ● ● ●● ● ● ● ● ● ●● ● ●● ● ● ●●● ● ●● ● ● ● ● ● ●● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ●●● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ●● ● ●● ● ● ●● ● ● ● ● ● ● ● ●●●● ● ● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●●● ●● ● ●● ●● ● ● ●●● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ●● ● ● ●● ● ● ● ●●● ● ● ● ●● ● ● ● ● ●● ● ●● ● ● ● ● ●● ● ● ● ● ●● ● ●● ● ● ● ● ● ●● ● ● ● ● ●●●● ● ● ●● ● ● ● ●● ● ● ●● ●●● ● ●● ●● ● ● ● ● ● ● ●●●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ●● ● ●● ●● ● ● ● ●● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ●●● ● ● ● ●● ●● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● • 5 URLs with score = 0 ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● 0.8 ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● • 85% of URLs with score ● ● ● ● ● ● ● ● ● ● ● ● ●● ● Mean Score ● ● ● ● ● ● 0.6 >=0.8 ● ● ● ● ● ● ● ● ●● ● ● ● • titles rarely change 0.4 ● drastically 0.2 0 ● ● ●● ● 0 200 400 600 800 1000 URLs 12
    45. Degree of Change Mean Scores of all Titles - Rooted 1 ●●●●●●●●●●●●●●●●●●●●● ● ● ●●●●● ● ●● ● ●● ●●●●●●● ●●●●●●●●● ●● ● ●● ●●●●● ●●● ● ● ●●● ●●●● ● ● ● ●● ●●● ●●● ●● ●●● ●●●● ●● ● ● ● ●● ● ● ● ● ● ●●● ●●● ●● ● ● ● ● ● ● ● ● ●● ● ● ●● ●● ● ● ● ●●●● ● ●● ● ●● ● ●●● ● ●● ● ●● ● ● ●● ● ● ●●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●●● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ●● ●● ●●● ●● ● ●● ● ● ● ● ●● ● ●● ● ● ● ●● ●● ● ●● ● ● ● ● ●●●● ● ● ●● ●● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ●● ● ● ●● ●● ● ● ● ●● ● ●● ● ● ● ●● ● ● ●●● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ●● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ●● ● ●● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● 0.8 ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● Mean Score ● ● ● ● ● ● ● ● ● ● ● ● ● ● 0.6 ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● 0.4 ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● 0.2 ● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● 0 ● ● ● ● ● ● ● ● ● 0 200 400 600 800 1000 URLs 13
    46. Degree of Change Mean Scores of all Titles - Rooted 1 ●●●●●●●●●●●●●●●●●●●●● ● ● ●●●●● ● ●● ● ●● ●●●●●●● ●●●●●●●●● ●● ● ●● ●●●●● ●●● ● ● ●●● ●●●● ● ● ● ●● ●●● ●●● ●● ●●● ●●●● ●● ● ● ● ●● ● ● ● ● ● ●●● ●●● ●● ● ● ● ● ● ● ● ● ●● ● ● ●● ●● ● ● ● ●●●● ● ●● ● ●● ● ●●● ● ●● ● ●● ● ● ●● ● ● ●●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●●● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ●● ●● ●●● ●● ● ●● ● ● ● ● ●● ● ●● ● ● ● ●● ●● ● ●● ● ● ● ● ●●●● ● ● ●● ●● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ●● ● ● ●● ●● ● ● ● ●● ● ●● ● ● ● ●● ● ● ●●● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ●● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● • 9 URLs with score = 0 ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● 0.8 ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● Mean Score ● ● ● ● ● ● ● ● ● ● ● ● ● ● 0.6 ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● 0.4 ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● 0.2 ● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● 0 ● ● ● ● ● ● ● ● ● 0 200 400 600 800 1000 URLs 13
    47. Degree of Change Mean Scores of all Titles - Rooted 1 ●●●●●●●●●●●●●●●●●●●●● ● ● ●●●●● ● ●● ● ●● ●●●●●●● ●●●●●●●●● ●● ● ●● ●●●●● ●●● ● ● ●●● ●●●● ● ● ● ●● ●●● ●●● ●● ●●● ●●●● ●● ● ● ● ●● ● ● ● ● ● ●●● ●●● ●● ● ● ● ● ● ● ● ● ●● ● ● ●● ●● ● ● ● ●●●● ● ●● ● ●● ● ●●● ● ●● ● ●● ● ● ●● ● ● ●●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●●● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ●● ●● ●●● ●● ● ●● ● ● ● ● ●● ● ●● ● ● ● ●● ●● ● ●● ● ● ● ● ●●●● ● ● ●● ●● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ●● ● ● ●● ●● ● ● ● ●● ● ●● ● ● ● ●● ● ● ●●● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ●● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● • 9 URLs with score = 0 ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● 0.8 ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● • 56% of URLs with score ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● >=0.8 Mean Score ● ● ● ● ● ● ● ● ● ● ● ● ● ● 0.6 ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● 0.4 ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● 0.2 ● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● 0 ● ● ● ● ● ● ● ● ● 0 200 400 600 800 1000 URLs 13
    48. Degree of Change Mean Scores of all Titles - Rooted 1 ●●●●●●●●●●●●●●●●●●●●● ● ● ●●●●● ● ●● ● ●● ●●●●●●● ●●●●●●●●● ●● ● ●● ●●●●● ●●● ● ● ●●● ●●●● ● ● ● ●● ●●● ●●● ●● ●●● ●●●● ●● ● ● ● ●● ● ● ● ● ● ●●● ●●● ●● ● ● ● ● ● ● ● ● ●● ● ● ●● ●● ● ● ● ●●●● ● ●● ● ●● ● ●●● ● ●● ● ●● ● ● ●● ● ● ●●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●●● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ●● ●● ●●● ●● ● ●● ● ● ● ● ●● ● ●● ● ● ● ●● ●● ● ●● ● ● ● ● ●●●● ● ● ●● ●● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ●● ● ● ●● ●● ● ● ● ●● ● ●● ● ● ● ●● ● ● ●●● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ●● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ●● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ●● • 9 URLs with score = 0 ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● 0.8 ● ●● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● • 56% of URLs with score ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● >=0.8 Mean Score ● ● ● ● ● ● ● ● ● ● ● ● ● ● 0.6 ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● • titles more likely to ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● change compared to ● ● ●● ● ● 0.4 ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● their first observation ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● 0.2 ● ● ● ● ●● ●● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● 0 ● ● ● ● ● ● ● ● ● 0 200 400 600 800 1000 URLs 13
    49. Concluding Remarks • Web pages’ titles are rather stable over time • Performance comparable to LSs • Suggested workflow within system: • Query title first • Generate and query LS second 14
    50. Concluding Remarks • Web pages’ titles are rather stable over time • Performance comparable to LSs • Suggested workflow within system: • Query title first • Generate and query LS second • Can we apply machine learning techniques to generate a title quality prediction model? 14
    51. Concluding Remarks • Web pages’ titles are rather stable over time • Performance comparable to LSs • Suggested workflow within system: • Query title first • Generate and query LS second • Can we apply machine learning techniques to generate a title quality prediction model? • What is the impact on title changes for dynamic vs static web pages? 14
    52. Investigating the Change of Web Pages’ Titles Over Time Questions? Martin Klein and Michael L. Nelson Old Dominion University {mklein,mln}@cs.odu.edu 15

    + Old Dominion UniversityOld Dominion University, 4 months ago

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