Ancient History Encyclopedia joins Pelagios

We are happy to announce that Ancient History Encyclopedia is joining the Pelagios project. Ancient History Encyclopedia is a non-profit digital humanities company with the aim of providing reviewed ancient history information on the web. All content is submitted by volunteer historians, authors, and enthusiasts and is reviewed by our editors before being published. We strongly believe in open access education, which is why all our content is free and available under a creative commons license.

Our mission is to make people interested in ancient history; we want to engage our global audience, by not only presenting the facts but also by doing it in an interesting way. We believe that "story" is a key component in the word "history", and we aim to convey in all our published content our belief that history is the greatest story ever written.

Despite being a story, history is not linear (as it is taught in most school coursebooks), but rather a very parallel type of story, where everything is interlinked. This is why digital media are much better-suited to history education than books of the dead-tree type (which we still love, of course). At AHE pieces of information are tagged and shared across different but related subjects, and each page is built automatically, taking precisely the information that is relevant for that subject from our database of definitions, articles, events, and maps.

Interactive Map of the Ancient World (WIP)

We adhere to academic standards when it comes to research and citations, but our readership is far more diverse than that of an academic publication. While we love pointing to new research, we mainly publish definitions and articles presenting the ancient past along lines commonly-accepted enough to enable a student to reference them in coursework and for an instructor to accept them without question.

Many high schools and undergraduate college courses around the world point to AHE in their reading lists or use it for course material. Our mission is to let everyone learn about ancient history in an engaging and easy-to-understand way. We want our readers to get excited about ancient history, and then we want to point them to the more detailed, academic, or original sources (both on our site and across the internet).

Joining Pelagios is simply the next logical step: The more history we manage to link together, the more our readers can "dig deeper" and get lost in ancient times. The easier it is for students to find the vast amount of material that all Pelagios contributors have assembled, the better. We are very excited to be part of the vast network of data coming from high-quality websites and established institutions alike!

Geographical information retrieval of historical regions

In the last few weeks I have been developing some API and an interface over the PELAGIOS API in order to be able to retrieve historical places, and their relative annotations, by using some geographical context. The issue of superimposing a geographical representation over some data collection is not novel. In modern data collections, for example the data produced by public administrations nowadays, organisations use geographical nomenclatures such as the administrative subdivisions, or the NUTS if the data is statistical observations. 

For historical data collections this is not always feasible, since the administrations of past kingdoms not always provided a sharp definition of their boundaries (sharp meant in a modern sense, with precise coordinates for regions' shapes) nor a deep subdivision which can help our information retrieval task.

Fortunately for PELAGIOS' users, some of the boundaries for the provinces of the past roman empire have been made available as shape files, and this can help us in browsing the wealth of data annotations provided as geolocalized linked data. The shape files in question were digitised from Barrington Atlas rasters (georegistered and supplied by AWMC) by Pedar Foss at Depauw University in 2007 within the context of the MAGIS project, and have been provided by Tom Elliott from the Institute for the Study of the Ancient World, New York University. The regions represented can be seen in the figure below.

Roman provinces up to AD 117 visualised in CartoDB

The present post is not about a single API or a single interface that can be implemented on top of PELAGIOS data and services, but instead it aims to provide some insights on how to implement geographical browsing by using open source tools. 

In order to visualize places and annotations from PELAGIOS API we exploited the geographical search by bounding box. By retrieving places in the PELAGIOS network contained by a bounding box we are half way to filter them via any polygon. In fact, by adopting a GIS we could directly querying data by polygons. Unfortunately that would require to have all the annotation data and the regions' polygons stored in the same database which is against the principle of distributeness of the linked data paradigm and it is not feasible in general scnarios. In fact that solution would require to provide a version of the PELAGIOS data to any interested user that would be forced to install GIS software and host their particular polygons. 

Instead, in here, what we did is to decouple the management of the annotation data with the geographical retrieval features, trying to minimize the amount of software to install and reusing as much as possible the data and services already provided. For this reason we uploaded the polygons we were interested on in a web enabled version of postgis, called CartoDB. CartoDB allows a limited and free use of the web platform, but users can download the open source version and install it on a server if and when needed. CartoDB allows to run SQL queries over HTTP requests that allow developers to integrate the system easily.

As said earlier, once we have the capability to query by bounding box we are half way to being able to query by polygons. In fact, by querying the CartoDB we can retrieve the shape of a region by using its name (e.g. Aquitania in the figures below). If we want to retrieve all the PELAGIOS places contained in the Aquitania region we can query the PELAGIOS API for the places contained in the bounding box of the polygon first, and then filter those places based on the topological containment applied to the retrieved shape. 

Selection of PELAGIOS places by using
region's bounding box

Filtering of those resources by using the
polygon topological containment 

The activities involved to extract places by using polygons can be represented by the diagram below and involve three actors: the service implemented by the ECS dept. in Southampton (named ECS), the PELAGIOS API, and the CartoDB instance used for this scenario.

Pelagios Phase 2: Project Plan

Phase two of Pelagios looks to build on our lightweight framework, based on the concept of place (a Pleiades URI) and a standard ontology (Open Annotation Collaboration), by publishing the Pelagios Toolkit-a set of services and documentation that will assist people in annotating, discovering and vizualizing references to places in open online ancient world resources.

In all, there are four Work-Packages:

§ WP1 casts the net beyond the existing partners in order to allow anyone to publish their data in a way that maximizes its discoverability. This webcrawling and indexing service will find material and - based on the Pelagios framwork and semantic sitemaps - aggregate place metadata in order to create value for the holders of that data.

§ WP2 aims to explore further ways of exploiting the concept of place. The place/space-based APIs and contextualisation service will help other users and data-providers discover relevant data and do interesting things with them.

§ WP3 tackles end-user engagement: i.e. subject specialists who lack the technical coding expertise to use the data underlying what it seen on the screen. The visualization service will explore ways of allowing these users to get to grips with the data both in a single Pelagios interface but also as embedded widgets hosted on each partner’s site.

§ WP4 distils the guidelines into a cookbook providing explicit recipes for producing, finding and making use of geoannotations for the community as a whole. In short, you won’t need to be a Pelagios partner to be able to join-in in making your data discoverable and usable.

The evolving nature of the Pelagios collective reflects the shift towards community engagement. While partners from the original Pelagios proof-of-concept project will continue to be involved, the main work for phase two of Pelagios will be carried out by: Arachne, CLAROS, DME, Fasti-online, GAP, IET (the Open University), Nomisma, Southampton, SPQR, the Ure Museum.

Deliverables

The outcomes, in more detail, are as follows:

D 1.1: Web Crawling and Indexing Prototype. This infrastructure component traverses resource sets on the Web (registered manually or discovered using semantic search engines like Sindice) and catalogues their place metadata. Place metadata encompasses geographical coordinates as well as Pleiades and Geonames URIs.

D 1.2: Pelagios 2 Graph API. This deliverable is an HTTP API that allows querying of the aggregate data graph generated by the Indexing Prototype. The API will provide responses in JSON and RDF format; and possibly in additional formats (e.g. KML or GeoRSS) if the need is identified in WP3. The initial range of possible queries is based on the outcome of the Pelagios project. The exact scope and structure of the final API will be driven by the requirements identified in WP3.

D 1.3: API Statistics and Reporting Interface. This deliverable will extend the Pelagios 2 Indexing Prototype with means to extract statistics and reports on the use of the API. Data partners can use this interface to gain insight into how their data is being discovered, queried and re-used within the larger online community.

D 2.1: Place-based API. This deliverable will extend the Pelagios 2 API with queries that return resources relevant to specific places or those with mereological (part-whole) relationships.

D 2.2: Space-based API. This deliverable will extend the Pelagios 2 API with queries that permit searches based on geographic scope, e.g. within a certain geographic buffer around a given location set.

D 2.3: Contextualisation Prototype. This deliverable is a service that provides ranked, relevant materials for a certain place or particular Named Entities. Results will be enriched with additional data from sources such as GeoNames, DBpedia and Freebase.

D 3.1: Evaluation of User Needs. This deliverable will report on the results of a formal evaluation of user needs regarding data visualization. The evaluation will be conducted in conjunction with project partners, and will inform the design of a set of online visualization widgets. This deliverable will have the form of a series of blog posts.

D 3.2: Widget Suite, Alpha version. This deliverable encompasses the first (alpha) version of the visualization widgets.

D 3.3: Evaluation of Widget Design. This deliverable will report on the results of observational and participatory design studies. The studies will be conducted on the Widgets as they are continuously and iteratively being developed from alpha state to final (beta) prototype. This deliverable will have the form of a series of blog posts.

D 3.4: Widget Suite, Beta version. This deliverable encompasses the final (beta) version of the visualization widgets.

D 4: Pelagios 2 Cookbook. Content Partners will produce regular documentation on data preparation, practices, tool use, etc. in the form of blog posts. The PI, assisted by the Co-Is will distil this information into a “cookbook” which will make it easier for anyone with Ancient World content to publish their data online in conformance with the Pelagios 2 common open standards.