  Video tutorials are a popular medium for informal and formal learning.
However, when learners attempt to view and follow along with these tutorials,
they encounter what we call gaps, that is, issues that can prevent learning. We
examine the gaps encountered by users of video tutorials for feature-rich
software, such as spreadsheets. We develop a theory and taxonomy of such gaps,
identifying how they act as barriers to learning, by collecting and analyzing
360 viewer comments from 90 Microsoft Excel video tutorials published by 43
creators across YouTube, TikTok, and Instagram. We conducted contextual
interviews with 8 highly influential tutorial creators to investigate the gaps
their viewers experience and how they address them. Further, we obtain insights
into their creative process and frustrations when creating video tutorials.
Finally, we present creators with two designs that aim to address gaps
identified in the comment analysis for feedback and alternative design ideas.
