Producing sentences which are perceived as natural by a human addressee-a property which we will denote as fluency 1 throughout this paper -is a crucial goal of all natural language generation (NLG) systems: it makes interactions more natural, avoids misunderstandings and, overall, leads to higher user satisfaction and user trust (Martindale and Carpuat, 2018).
fluency evaluation is important, e.g., during system development, or If access to a synonym dictionary is likely to be of use, then this package may 3 be of service.