1.
CLEAR: a Credible Live
Evaluation Method of
Website Archivability
Vangelis Banos1, Yunhyong Kim2, Seamus Ross2, Yannis Manolopoulos1
1Department of Informatics, Aristotle University, Thessaloniki , Greece
2University of Glasgow, United Kingdom
ARCHIVEREADY.COM

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Table of Contents
1. Problem definition and related work,
2. Our contributions,
3. Website Archivability,
4. CLEAR: A Credible Live Method to
Evaluate Website Archivability,
5. Demonstration: http://archiveready.com/,
6. Limitations and Future Work.

3.
Problem definition
• Web content acquisition is a critical step in the
process of web archiving;
• If the initial Submission Information Package lacks
completeness and accuracy for any reason (e.g.
missing or invalid web content), the rest of the
preservation processes are rendered useless;
• There is no guarantee that web bots dedicated to
retrieving website content can access and retrieve
it successfully;
• Web bots face increasing difficulties in
harvesting websites.
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4.
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• After web harvesting, administrators review
manually the content and endorse or reject the
harvested material.
• Web harvesting is automated while Quality
Assurance (QA) is manual.
• Efforts to deploy crowdsourced techniques to
manage QA provide an indication of how significant
the bottleneck is.
Problem definition

5.
Inspired by our work at
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There is a need for a method to assess
website archive readiness in order to
support web archiving workflow.
building a blog preservation software platform
http://blogforever.eu

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1. the introduction of the notion of Website
Archivability,
2. the definition of the Credible Live
Evaluation of Archive Readiness
(CLEAR) method to measure Website
Archivability
3. ArchiveReady.com, a web application
which implements the proposed method.
Our Contributions

7.
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1. Mechanism to improve the quality of web archives.
2. Expand and optimize the knowledge and practices of
web archivists, supporting them in their decision
making, and risk management.
3. Standardize the web aggregation practices of web
archives, especially QA.
4. Foster good practices in web development, make
sites more amenable to harvesting, ingesting, and
preserving.
5. Raise awareness among web professionals regarding
preservation.
Our Aims

8.
Website
Archivability ?
What is
Website Archivability captures the core aspects
of a website crucial in diagnosing whether it has
the potentiality to be archived with
completeness and accuracy.
Attention! it must not be confused with website
dependability, reliability, availability, safety, security, survivability,
maintainability.

9.
CLEAR: A Credible Live Method to Evaluate
Website Archivability
• An approach to producing on-the-fly measurement
of Website Archivability,
• Web archives communicate with target websites via
standard HTTP,
• Information such as file types, content and transfer
errors could be used to support archival decisions,
• We combine this kind of information with an
evaluation of the website's compliance with
recognised practices in digital curation,
• We generate a credible score representing the
archivability of target websites.
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Accessibility Cohesion
Standards
Compliance
Performance
Metadata
CLEAR: A Credible Live Method to Evaluate
Website Archivability

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Website attributes evaluated using CLEAR

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C L E A R
• The method can be summarised as follows:
1. Perform specific Evaluations on Website
Attributes,
2. In order to calculate each Archivability Facet’s
score,
• Scores range from (0 – 100%),
• Not all evaluations are equal, if an important
evaluation fails, score = 0, if a minor
evaluation fails, score = 50%
3. Producing the final Website Archivability as the
sum all Facets’ scores.

13.
Accessibility
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14.
Accessibility
• A website is considered accessible only if web
crawlers are able to visit its home page, traverse its
content and retrieve it via standard HTTP requests.
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15.
Accessibility
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Facet Evaluation Rating Total
Accessibility
No RSS feed 50%
50%
No robots.txt 50%
No sitemap.xml 0%
6 links, all valid 100%
http://ipres2013.ist.utl.pt/ Website Archivability evaluation on 23rd April 2013

16.
Cohesion
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17.
Cohesion
• Relevant to:
• Efficient operation of web crawlers,
• Management of dependancies with digital
curation.
• If files constituting a single website are dispersed
across different web locations, the acquisition and
ingest is likely to risk suffering if one or more web
locations fail.
• Changes that occur outside the website are not
going to affect it if it does not use 3rd party
resources.
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18.
Cohesion
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Facet Evaluation Rating Total
Cohesion
1 external and no internal scripts 0%
70%
4 local and 1 external images 80%
No proprietary (Quicktime & Flash)
files
100%
1 local CSS file 100%
http://ipres2013.ist.utl.pt/ Website Archivability evaluation on 23rd April 2013

19.
Metadata
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20.
Metadata
• The adequate
provision of metadata
has been a
continuing concern
within digital curation.
• The lack of metadata
impairs the archive’s
ability to
manage, organise, re
trieve and interact
with content
effectively.
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21.
Metadata
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Facet Evaluation Rating Total
Metadata
Meta description found 100%
87%
HTTP Content type 100%
HTTP Page expiration not found 50%
HTTP Last-modified found 100%
http://ipres2013.ist.utl.pt/ Website Archivability evaluation on 23rd April 2013

22.
Performance
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23.
Performance
Performance is an important aspect of web archiving.
The throughput of data acquisition of a web spider
directly affects the number and complexity of web
resources it is able to process.
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Facet Evaluation Rating Total
Performance Average network response
time is 0.546ms
100% 100%
http://ipres2013.ist.utl.pt/ Website Archivability evaluation on 23rd April 2013

24.
Standards
Compliance
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25.
Standards Compliance
• Compliance with standards is a recurring theme in
digital curation practices. It is recommended that for
digital resources to be preserved they need to be
represented in known and transparent standards.
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26.
Standards Compliance
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Facet Evaluation Rating Total
Standards
Compliance
1 Invalid CSS file 0%
87%
Invalid HTML file 0%
Meta description found 100%
No HTTP Content encoding 50%
HTTP Content Type found 100%
HTTP Page expiration found 100%
HTTP Last-modified found 100%
No Quicktime or Flash objects 100%
5 images found and validated with JHOVE 100%
http://ipres2013.ist.utl.pt/ Website Archivability evaluation on 23rd April 2013

27.
iPRES 2013 Website Archivability Evaluation
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Facet Rating Website
Archivability
Accessibility 50%
77%
Cohesion 70%
Standards Compliance 77%
Metadata 87%
Performance 100%

28.
ArchiveReady.com
Demonstration
- Web application implementing CLEAR,
- Web interface & also Web API in JSON,
- Running on Linux, Python, Nginx, Redis, Mysql.
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Impact
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1. Web professionals
- evaluate the archivability of their websites
in an easy but thorough way,
- become aware of web preservation concepts,
- embrace preservation-friendly practices.
2. Web archive operators
- make informed decisions on archiving websites,
- perform large scale website evaluations with ease,
- automate web archiving Quality Assurance,
- minimise wasted resources on problematic websites.

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Limitations & Future Work
1. Not optimal to treat all Archivability Facets as equal.
2. Evaluating a single website page, based on the
assumption that web pages from the same website
share the same components and standards.
Sampling would be necessary.
3. Certain classes and specific types of errors create
lesser or greater obstacles to website acquisition
and ingest than others. The method needs to be
enhanced to reflect this differential valuing of error
classes and types.

32.
THANK YOU
Vangelis Banos
Web: http://vbanos.gr/
Email: vbanos@gmail.com
ANY QUESTIONS?
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The research leading to these results has
received funding from the European
Commission Framework Programme 7
(FP7), BlogForever project, grant
agreement No.269963.