The communication matrix was published and reviewed by Dr Charity Rowland of Oregon Health and Science University. The assessment is designed for use with children who have complex communication needs to assist in documenting the development of expressive communication skills. It is administered by interviewing the child’s parents and teachers to document communication behaviours in everyday settings and situations. Administration can take between ten minutes and one hour and depends on the amount of communication behaviours a child is using. The assessment covers seven levels of communication (from pre-intentional communication through to language), four main reasons to communicate (such as obtaining objects or desired information and social interaction) and twenty-four specific intents or communicative functions.