Mercurial > hg > cc > work

<?xml version='1.0'?>
<?xml-stylesheet type="text/xsl" href="../../../lib/xml/doc.xsl" ?>
<!DOCTYPE doc SYSTEM "../../../lib/xml/doc.dtd" >
<doc xmlns:x="http://www.w3.org/1999/xhtml">
 <head>
  <title>LURID3: Longitudinal studies of the World Wide Web<x:br/>
  <span style="font-size:80%">UKRI reference APP39557</span></title>
  <author>Henry S. Thompson</author>
  <date>22 Apr 2024</date>
 </head>
 <body>
  <div>
   <title>Vision</title>
   <div>
    <title>Motivation</title>
    <p>Empirical evidence of how use of the Web has changed in the past provides crucial input to decisions about its future.   Creative uses of the mechanisms the Web provides expand its potential, but also sometimes put it at risk, so it’s worrying that there’s surprisingly little empirical evidence available to guide standardization and planning more generally. Which aspects of the Web’s functionality are widely used? Hardly ever used? How is this changing over time?</p>
    <p>The kind of evidence needed to answer such questions is hard to come by.
  The proposed research builds on our previous work in this area [Thompson and
Tong 2018], [Chen 2021], [Thompson 2024], taking advantage of the computational resource Cirrus provides to validate and expand our work on the Common Crawl web archive.</p>
    <p>Common Crawl (CC) is a very-large-scale web archive, containing
petabytes of data from more than 65 monthly/bi-monthly archives, totalling over
100 billion web pages.  Collection began in 2008 with annual archives,
expanding steadily to the point that since 2017 archives were collected monthly
until 2023, since when it's been bi-monthly. Recent archives contain over
3x10^9 pages, about 75 Terabytes (compressed).  Together with Edinburgh colleagues we have created local copies of 8 months of CC in a petabyte store attached to Cirrus.  For our purposes it is important to note that the overlap between any two archives as measured by Jaccard similarity of page checksums is less than .02 [Nagel 2022].</p>
    <p>The very large size of CC's constituent archives makes using it for research, particularly
longitudinal studies, which necessarily involve multiple archives, very
expensive in terms of compute time and storage space and/or web bandwidth. The proposed work will build on our just-completed project
(<name>LURID2: Assessing the validity of Common Crawl</name>, EPSRC Access to
HPC Award from 2022&ndash;12 to 2023&ndash;04).  As reported in [Thompson
2024], the two main results of that project for
addressing the expense problem are based on exploiting and extending the much smaller (&lt;200 gigabytes (GB) compressed) <emph>index</emph> which is available for each archive, as follows:</p>
    <list>
     <item>By adding Last-Modified timestamps to the index we enable
fine-grained longitudinal exploration using only a single archive;</item>
     <item>By comparing the distribution of index features for each of the 100
segments into which each archive is packaged for access with their distribution over the whole archive, we identified the least and most representative segments for a number of recent archives. Using this allows the segment(s) that are most representative of an archive to be used as proxies for the whole.</item>
    </list>
    <p>Combining these two approaches allowed us to produces a fine-grained
analysis of how URI lengths have changed over time, leading to an unanticipated
insight into the how the process of creating of Web pages <emph>itself</emph> has changed.</p>
   </div>
   <div>
    <title>Objectives</title>
    <list type="1defn">
     <item term="Objective 1: Foster research">The augmented index form
CC's August 2019 data is now available online.  In </item>
    </list>
   </div>
  </div>
  <div>
   <title>Approach</title>
  </div>
 </body>
</doc>
author	Henry S. Thompson <ht@inf.ed.ac.uk>
date	Wed, 09 Oct 2024 22:55:27 +0100
parents	052f4ff4eae6
children