Graphical, type-checking dependency tree editor

The process of marking up the syntactic structure of the sentences in a corpus is facilitated by having a graphical tree editor. A type specification constraints the nature of acceptable trees, and visual indication of non-conformities makes corrections easy. Projectivity checking can also be a useful way to notice errors, depending on the linguistic design of the tree type specification. A small test corpus has been marked up using this method. Only the English language has been investigated so far, and the tool takes no other input than the type specification and the corpus. Adding a lexical database is an obvious way to make it more generally useful.