Introduction
The introduction briefly explains Linked Data, addresses the concept of FAIR data, and explains the process of converting tabular data to Linked Data.
Linked Data was conceived by Tim Berners-Lee in 2008 for what he called the Semantic Web.
The Semantic Web is a vision: the idea of having data on the Web defined and linked in a way that it can be used by machines not just for display purposes, but also for automation, integration and reuse of data across various applications.[1]
The Semantic Web is based on the Resource Description Framework (RDF) consisting of triples. A triple contains a subject (i.e. Fumes), a predicate or property (i.e. has occupation) and an object or value (i.e. chimney sweep).
Each part of the triple can be a Uniform Resource Identifier (URI) that may or may not link to a URL.
The FAIR principles advise any researcher to make their data findable, accessible, interoperable, and reusable.[2] Tim Berners-Lee envisioned Linked Data as Linked Open Data. Data stored in proprietary formats (e.g. Excel, Access, SPSS) is not accessible, nor interoperable. CoW thus starts from a text file for tabular data called a .csv (comma-separated values).
To create Linked Data from your .csv file, we follow a three step procedure.
- We ask CoW to generate a JSON-schema (a sort of recipe) based on our .csv file.
- We improve on this automatically derived JSON-schema, by manually adding the specifics of our .csv such as provenance, and links to other data.
- We ask CoW to generate Linked Data, based on our .csv file and bespoke JSON-schema.
The process of converting a .csv file to Linked Data thus requires a piece of software called CoW. While the installation instructions are provided, for people not used to working with the command line it has proved to be a hassle. We therefore provide an image in a virtualization engine that allows you to use CoW without installing it. The image is hosted by Docker, and available here.
The Docker image has to be set up correctly before getting started (see sharing files between the host and the container). Next, follow the same three steps mentioned above:
- Copy the file path of the .csv file you want to upload from the shared folder. In your browser ask CoW to create the JSON-schema based on this .csv file.
- To modify the JSON-schema, open the metadata file from the shared folder on your computer. More information on the template format can be found here.
- In the browser ask CoW to generate Linked Data. The .nq file will be in the shared folder on your computer.
From the next section onwards, we'll explain the various parts of the JSON-schema and how to augment it.
[1] V. Kashyap, C. Bussler, and M. Moran. 2008. The Semantic Web: Semantics for Data and Services on the Web. Data-Centric Systems and Applications. Springer Berlin Heidelberg, 2008, 3.
[2] M.D. Wilkinson et al. 'The FAIR Guiding Principles for Scientific Data Management and Stewardship,' Scientific Data, 3 (2016): 1-9.