  User experience in data visualization is typically assessed through
post-viewing self-reports, but these overlook the dynamic cognitive processes
during interaction. This study explores the use of mind wandering -- a
phenomenon where attention spontaneously shifts from a primary task to
internal, task-related thoughts or unrelated distractions -- as a dynamic
measure during visualization exploration. Participants reported mind wandering
while viewing visualizations from a pre-labeled visualization database and then
provided quantitative ratings of trust, engagement, and design quality, along
with qualitative descriptions and short-term/long-term recall assessments.
Results show that mind wandering negatively affects short-term visualization
recall and various post-viewing measures, particularly for visualizations with
little text annotation. Further, the type of mind wandering impacts engagement
and emotional response. Mind wandering also functions as an intermediate
process linking visualization design elements to post-viewing measures,
influencing how viewers engage with and interpret visual information over time.
Overall, this research underscores the importance of incorporating mind
wandering as a dynamic measure in visualization design and evaluation, offering
novel avenues for enhancing user engagement and comprehension.
