FoLiA: A practical XML format for linguistic annotation – a descriptive and comparative study

Abstract

In this paper we present FoLiA, a Format for Linguistic Annotation, and conduct a comparative study with other annotation schemes, including the Linguistic Annotation Framework (LAF), the Text Encoding Initiative (TEI) and Text Corpus Format (TCF). An additional point of focus is the interoperability between FoLiA and metadata standards such as the Component MetaData Infrastructure (CMDI), as well as data category registries such as ISOcat. The aim of the paper is to present a clear image of the capabilities of FoLiA and how it relates to other formats. This should open discussion and aid users in their decision for a particular format.

FoLiA is a practically-oriented XML-based annotation format for the representation of language resources, explicitly supporting a wide variety of annotation types. It introduces a flexible and uniform paradigm and a representation independent of language or label set. It is designed to be highly expressive, generic, and formalised, whilst at the same time focussing on being as practical as possible to ease its adoption and implementation. The aspiration is to offer a generic format for storage, exchange, and machine-processing of linguistically annotated documents, preventing users as well as software tools from having to cope with a wide variety of different formats, which in the field regularly causes convertibility issues and proliferation of ad-hoc formats. FoLiA emerged from such a practical need in the context of Computational Linguistics in the Netherlands and Flanders. It has been successfully adopted by numerous projects within this community. FoLiA was developed in a bottom-up fashion, with special emphasis on software libraries and tools to handle it.