Daniel Gomes edited this page Nov 18, 2016 · 8 revisions


The PWA9609 test collection was created to support research on web archive information retrieval (WAIR). It is composed by three parts: (1) a corpus representative of the documents' versions encountered in a real search environment; (2) a set of topics describing users' information needs; and (3) relevance judgments (a.k.a. qrels) indicating the degree of relevance of each document retrieved for each topic.

If you are experimenting with WAIR systems and you are interested in their design and evaluation, then this collection can be useful.


The corpus is composed by 6 collections of the Portuguese web, broadly considered the web subset of interest to the Portuguese. These collections are indexed and searchable through the public access given by the Portuguese Web Archive (PWA) at http://archive.pt.

In total, the corpus contains 255 million web pages' versions collected between 1996 and 2009. It amounts 6.2TB compressed in ARC file format (8.9 TB uncompressed). The corpus' main characteristics are detailed in the following table, showing a significant heterogeneity in age, size and type.

# Years Documents (K) Size (GB) Description
1 1996 75 0.316 selective crawl of most popular sites
2 1996 - 2000 5 047 48 broad crawls periodically made by the Internet Archive
3 2000 - 2008 118 842 1 900 broad crawls periodically made by the Internet Archive
4 2004 - 2006 14 374 165 selective crawls made by the Portuguese National Library
5 2008 48 718 1 600 exhaustive crawl of mostly the .pt domain
6 2009 68 776 2 500 exhaustive crawl of mostly the .pt domain
TOTAL 255 832 6 213

This corpus includes all types of media formats (e.g. text, image, video and audio) and genres (e.g. news, blogs, wikis) to support future IR tasks with different goals in mind.

Obtaining a Copy of the PWA9609 test collection

The PWA9609 test collection is distributed by the Portuguese Foundation for National Scientific Computation strictly for research purposes only. The collection may be obtained by signing a data license agreement with the Portuguese Foundation for National Scientific Computing.

Please contact miguel.costa (at) fccn.pt for further information.


Relevance Judgments

Grade Very relevant Relevant Not relevant
manual 69 91 1 819
automatic 5 168 5 571 257 083
TOTAL 5 237 5 662 258 902


A list of mappings between each version id and the corresponding <URL, timestamp> pair can be downloaded.


Results can be computed with the trec_eval tool used by the TREC community, since the test collection follows the TREC file formats.

Other Issues

Information about the methodology used to create the PWA9609 collection was published at the 13th International Conference on Web Information System Engineering in a paper named Evaluating Web Archive Search Systems.

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