  Large language models (LLMs) are shaping a new user interface (UI) paradigm
in writing tools by enabling users to generate text through prompts. This
paradigm shifts some creative control from the user to the system, thereby
diminishing the user's authorship and autonomy in the writing process. To
restore autonomy, we introduce Textfocals, a UI prototype designed to
investigate a human-centered approach that emphasizes the user's role in
writing. Textfocals supports the writing process by providing LLM-generated
summaries, questions, and advice (i.e., LLM views) in a sidebar of a text
editor, encouraging reflection and self-driven revision in writing without
direct text generation. Textfocals' UI affordances, including contextually
adaptive views and scaffolding for prompt selection and customization, offer a
novel way to interact with LLMs where users maintain full authorship of their
writing. A formative user study with Textfocals showed promising evidence that
this approach might help users develop underdeveloped ideas, cater to the
rhetorical audience, and clarify their writing. However, the study also showed
interaction design challenges related to document navigation and scoping,
prompt engineering, and context management. Our work highlights the breadth of
the design space of writing support interfaces powered by generative AI that
maintain authorship integrity.
