In Natural Language Generation (NLG), sentence aggregation is the process of deciding which information to present in individual sentences. Not every message in a text plan needs to be expressed in a separate sentence; combining multiple messages into a single sentence can make the generated text more fluid and readable. While aggregation can be difficult to define generally, it ranges from redundancy elimination to linguistic structure combination. Furthermore, aggregation at the syntactic level only accounts for relatively small reductions compared to aggregation at the message level.