Universal Dependencies (UD) is a framework for the representation of grammar across different languages that aims to create a consistent and universal syntactic structure. The goal of UD is to provide a common linguistically motivated framework for annotating the grammatical relationships between words in a sentence, making it easier to compare linguistic phenomena across languages and to develop natural language processing (NLP) tools that can work with multiple languages.
Articles by others on the same topic
Universal Dependencies is a framework for comparable grammatical annotation across languages. It combines part of speech labels, morphological features and typed syntactic dependencies, while allowing documented language-specific choices. The framework supplies a common representation rather than a claim that all languages express every distinction identically.[ref]
Universal Dependencies annotation guidelines. project introduction and Morphology: General Principles, representation layers
For
Birds fly, a compatible analysis identifies Birds as a noun with plural grammatical number, gives it the lemma bird, and links it to fly with the subject relation nsubj. These are distinct annotation decisions: changing a lexical convention need not require changing the sentence's dependency structure.Basic dependencies form a rooted tree, whereas an enhanced representation can contain additional relations and need not remain a tree.[ref]
Universal Dependencies annotation guidelines. Syntax: General Principles, basic versus enhanced representation
Keeping the layers explicit helps compare parser output and manually analyzed text corpus resources. A valid interchange file and an empirically justified grammatical analysis remain different achievements.