  A surge of advances in language models (LMs) has led to significant interest
in using LMs to build co-writing systems, in which humans and LMs interactively
contribute to a shared writing artifact. However, there is a lack of studies
assessing co-writing systems in interactive settings. We propose a
human-centered evaluation framework, Parachute, for interactive co-writing
systems. Parachute showcases an integrative view of interaction evaluation,
where each evaluation aspect consists of categorized practical metrics.
Furthermore, we present Parachute with a use case to demonstrate how to
evaluate and compare co-writing systems using Parachute.
