  We propose a text editor to help users plan, structure and reflect on their
writing process. It provides continuously updated paragraph-wise summaries as
margin annotations, using automatic text summarization. Summary levels range
from full text, to selected (central) sentences, down to a collection of
keywords. To understand how users interact with this system during writing, we
conducted two user studies (N=4 and N=8) in which people wrote analytic essays
about a given topic and article. As a key finding, the summaries gave users an
external perspective on their writing and helped them to revise the content and
scope of their drafted paragraphs. People further used the tool to quickly gain
an overview of the text and developed strategies to integrate insights from the
automated summaries. More broadly, this work explores and highlights the value
of designing AI tools for writers, with Natural Language Processing (NLP)
capabilities that go beyond direct text generation and correction.
