An Introduction to Peripleo 2 – Pelagios Commons’ Linked Data Exploration Engine

Posted on 16 October 2017

Talk: Rebecca Kahn (HIIG), Leif Isaksen (Uni Exeter), Elton Barker (OU), Rainer Simon (AIT), Valeria Vitale (ICS), “An Introduction to Peripleo 2 – Pelagios Commons’ Linked Data Exploration Engine”.


Date: Monday, 16 October 2017

Time: starting at 17:00 c.t. (i.e. 17:15)

Venue: Humboldt-Universität zu Berlin, Gebäude Hausvogteiplatz (Raum 0319). Address: Hausvogteipl. 5-7, 10117 Berlin map


Peripleo is one of a suite of tools produced by Pelagios Commons, alongside Recogito, a tool which allows users to create semantic web annotations of maps and texts, without requiring a background in or extensive knowledge of Linked Data. Peripleo is Greek for “to sail (or swim) around”. The tool embodies the notion of being able to freely navigate the “sea of open data”, collectively brought together by our partners (and allowing users to discover the treasures hidden in remote places and ancient times).

Peripleo enables users to explore the geographic, temporal and thematic composition of distributed digital collections in their entirety, and then to progressively filter and drill down to explore individual records. It was developed with the conviction that an interface which empowers users to tap into and navigate heterogeneous online collections is crucial in order to demonstrate the utility of lightweight linking approaches, and to make their benefits more tangible to end-users and non-technical specialists. On a technical level, we feel that the loose coupling that exists between Peripleo and the resources it makes searchable is very much in the spirit of Linked Open Data, in contrast to more tightly coupled traditional search frontends which are typically bound to a specific repository.

A key design goal was to provide, on the one hand, a familiar Google-Maps-like interface, with full-text search and auto-completion; while allowing free-form modes of exploration on the other. In this “exploration mode”, Peripleo conveys a sense of the scope, breadth and structure of the data as a whole, by representing geographic coverage on the map, showing temporal spread as a histogram; and graphically illustrating distribution across different thematic facets (such as document language or data source). This way, users can easily gain an overview first, and then filter and drill down according to their own interests. Peripleo also functions as a service, and provides an API that enables other sites to re-use Pelagios data, either by building their own mashups or by embedding and linking to Peripleo search results easily.

The new version of Peripleo features various user interface enhancements, and a transition to a more scalable backend technology (ElasticSearch). Other additions include: a new data model that supports search, filtering and linking along People and Time Period entities, rather than just Places; and ‘entity aware’ full-text search.

Peripleo was awarded ‘Best Visualisation Tool’ award at the 2016 DH awards, and we are excited to demonstrate the next version of the software – and encourage members of the Digital Classicist community to experiment with it for their own research, and provide us with feedback.