The Encyclopedia of Life v2: Providing Global Access to Knowledge About Life on Earth

Abstract

The Encyclopedia of Life (EOL, http://eol.org) aims to provide unprecedented global access to a broad range of information about life on Earth. It currently contains 3.5 million distinct pages for taxa and provides content for 1.3 million of those pages. The content is primarily contributed by EOL content partners (providers) that have a more limited geographic, taxonomic or topical scope. EOL aggregates these data and automatically integrates them based on associated scientific names and other classification information. EOL also provides interfaces for curation and direct content addition. All materials in EOL are either in the public domain or licensed under a Creative Commons license. In addition to the web interface, EOL is also accessible through an Application Programming Interface. In this paper, we review recent developments added for Version 2 of the web site and subsequent releases through Version 2.2, which have made EOL more engaging, personal, accessible and internationalizable. We outline the core features and technical architecture of the system. We summarize milestones achieved so far by EOL to present results of the current system implementation and establish benchmarks upon which to judge future improvements. We have shown that it is possible to successfully integrate large amounts of descriptive biodiversity data from diverse sources into a robust, standards-based, dynamic, and scalable infrastructure. Increasing global participation and the emergence of EOL-powered applications demonstrate that EOL is becoming a significant resource for anyone interested in biological diversity.

Figure 1.

EOL v2 Homepage. When a member is logged in, the upper right corner of the page features links to member profile, personalized newsfeeds, and other information. Below the site search box, the "March of Life" thumbnails provide links to a sample of taxon pages drawn at random from pages above a minimal richness threshold. Two columns then feature EOL-related news items and an overview of recent community activity, followed by selected site statistics with a link to more detailed statistics over time. The site footer provides quick access to gateway pages (see below) and other site documentation.

Figure 2.

The Overview tab is the default view of an EOL taxon page. It features a sample of images, including a map, if available, a taxon hierarchy with links to other pages, a brief introduction to the taxon (if available), an activity feed, and links to relevant collections and communities.

Figure 3.

High-level data flow from content partners into EOL. Content partners make available EOL data transfer documents (resource documents) that are periodically indexed by EOL. These provide names, name hierarchies, and associated data objects to EOL. EOL aggregates these data and presents them on Taxon Pages. The content assigned to a Taxon Page can be reviewed, hidden, or reassigned to other Taxon Pages by EOL Curators.

Figure 4.

The EOL richness score is the sum of three weighted components: breadth, depth, and diversity. Breadth considers the different media types of information objects (including the number of different subjects available for text), depth considers both average and total number of words in text objects, and diversity considers the number of different sources of information, or providers. Normalized object values are scaled to be between 0 and 1 and put on a log-based scale such that the first objects counts more than the second up to a chosen limit at which point the value is 1 and additional objects of that type have no impact on the richness. The final score is multiplied by 100, so that it ranges from 0 to 100. For more detailed information, see http://eol.org/info/richness_score.

Figure 5.

Software stack for the production EOL web-servers. The vast majority of the code written specifically for EOL is in Ruby – which handles the website and the API – and PHP, which handles the content import process and provides some administrative interfaces.

Figure 6.

Growth in Encyclopedia of Life from 2008-2013. A. Taxon pages with content (at least one text article, image, map, video, or sound) (Suppl. material 1). B. Published resources (content import files). A provider may submit more than one resource file, for example when providing different kinds of content (Suppl. material 2). C. Registered EOL members (Suppl. material 3).

Figure 7.

Distribution of Creative Commons and other licenses for data objects on EOL. CC-BY = Creative Commons Attribution license; NC = Non-commercial restriction; SA = Share-alike restrictions. Objects with gnu-gpl/gnu-fdl licenses (3903 images and 21 text articles) are not shown. Overall, as of July 2013, EOL has 3,192,609 text articles, 1,812,295 images, 806,664 maps, 30,366 sounds, and 10,219 videos (Suppl. material 4).

Figure 8.

Activity patterns of EOL Assistant Curators compared to Full and Master Curators. Only Full and Master Curators can select preferred classifications and change the visibility and trust status of text and multimedia objects. Data Object curation by Assistant Curators is limited to adding associations between Data Objects and taxa.

Figure 9.

Data Object rating patterns of EOL members in relation to their curator status. Five stars is the highest rating, while one star is the lowest rating a member can give a text or multimedia object.

Figure 10.

Unique visitors to EOL per month, September 2011-January 2014, per Google Analytics.

Figure 11.

Global Rank for biodiversity web sites per http://www.alexa.com/, 02/26/2014. The rank is calculated using a combination of average daily visitors to this site and pageviews on this site over the past 3 months. Lower numbers indicate greater importance, as the site with the highest combination of visitors and pageviews is ranked #1. Note however that Alexa rankings are known to be subject to considerable sampling bias since they are largely based on the behavior of users browsing with an Alexa-compatible toolbar (Lo and Sharma Sedhain 2006).

Figure 12.

Google PageRank™ of various biodiversity websites, per http://www.prchecker.info/, 02/22/2014. Larger numbers indicate greater importance, and webpages with a higher PageRank are more likely to appear at the top of Google search results.