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

  • 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
  • The Problem 2
  • The Problem http://www.pspcentral.org/events/annual_meeting_2003.html 2
  • The Problem http://www.pspcentral.org/events/annual_meeting_2003.html 2
  • The Problem http://www.pspcentral.org/events/annual_meeting_2003.html 2
  • The Problem http://www.pspcentral.org/events/annual_meeting_2003.html 2
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • Dataset Length = 1 Length = 2 foo.bar/ foo.bar/bar/ foo.bar/index.html foo.bar/bar/index.html 8
  • Dataset Length = 1 Length = 2 foo.bar/ foo.bar/bar/ foo.bar/index.html foo.bar/bar/index.html 8
  • Dataset Length = 1 Length = 2 foo.bar/ foo.bar/bar/ foo.bar/index.html foo.bar/bar/index.html 8
  • Dataset Length = 1 Length = 2 foo.bar/ foo.bar/bar/ foo.bar/index.html foo.bar/bar/index.html 8
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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