GCS: a grammatical coding system for natural language data.

This article presents a rationale and description of GCS, or Grammatical Coding System. GCS is a general-use grammatical coding system designed for research on the language of normal and language-impaired children or adults and is especially useful for studies in which a relatively large number of participants are involved. It implements recent theoretical developments in linguistics to characterize development and/or language disorder in children and adults.