clear: a credible live evaluation method of website archivability, ipres2013
DESCRIPTION
Abstract: Web archiving is crucial to ensure that cultural, scientific and social heritage on the web remains accessible and usable over time. A key aspect of the web archiving process is optimal data extraction from target websites. This procedure is difficult for such reasons as, website complexity, plethora of underlying technologies and ultimately the open-ended nature of the web. The purpose of this work is to establish the notion of Website Archivability (WA) and to introduce the Credible Live Evaluation of Archive Readiness (CLEAR) method to measureWA for any website. Website Archivability captures the core aspects of a website crucial in diagnos- ing whether it has the potentiality to be archived with com- pleteness and accuracy. An appreciation of the archivability of a web site should provide archivists with a valuable tool when assessing the possibilities of archiving material and influence web design professionals to consider the implications of their design decisions on the likelihood could be archived. A prototype application, archiveready.com, has been established to demonstrate the viabiity of the proposed method for assessing Website Archivability.TRANSCRIPT
CLEAR: a Credible Live Evaluation Method of Website Archivability
Vangelis Banos1, Yunhyong Kim2, Seamus Ross2, Yannis Manolopoulos1
3 SEPT 2013 ▪ LISBON
1Department of Informatics, Aristotle University, Thessaloniki , Greece2University of Glasgow, United Kingdom
ARCHIVEREADY.COM
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Table of Contents1. 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.
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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• 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
Inspired by our work at
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There is a need for a method to assesswebsite 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
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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
WebsiteArchivability ?
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.
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
StandardsCompliance 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.
Accessibility
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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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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
Cohesion
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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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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
Metadata
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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, retrieve and interact with content effectively.
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Metadata1. What is it2. How is it calculated
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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
Performance
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PerformancePerformance 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
StandardsCompliance
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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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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
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%
ArchiveReady.comDemonstration
- 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 Work1. 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.
THANK YOUVangelis BanosWeb: http://vbanos.gr/Email: [email protected]
ANY QUESTIONS?
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The research leading to these results hasreceived funding from the European Commission Framework Programme 7 (FP7), BlogForever project, grant agreement No.269963.