  Written language is a useful tool for non-visual creative activities like
writing essays and planning searches. This paper investigates the integration
of written language in to the visualization design process. We create the idea
of a 'writing rudder,' which acts as a guiding force or strategy for the
design. Via an interview study of 24 working visualization designers, we first
established that only a minority of participants systematically use writing to
aid in design. A second study with 15 visualization designers examined four
different variants of written rudders: asking questions, stating conclusions,
composing a narrative, and writing titles. Overall, participants had a positive
reaction; designers recognized the benefits of explicitly writing down
components of the design and indicated that they would use this approach in
future design work. More specifically, two approaches - writing questions and
writing conclusions/takeaways - were seen as beneficial across the design
process, while writing narratives showed promise mainly for the creation stage.
Although concerns around potential bias during data exploration were raised,
participants also discussed strategies to mitigate such concerns. This paper
contributes to a deeper understanding of the interplay between language and
visualization, and proposes a straightforward, lightweight addition to the
visualization design process.
