  Previous studies conclusively show that pencil-and-paper lecture-tutorials
(LTs) are incredibly effective at increasing student engagement and learning
gains on a variety of topics when compared to traditional lecture. LTs in
astronomy are post-lecture activities developed with the intention of helping
students engage with conceptual and reasoning difficulties around a specific
topic with the end goal of them developing a more expert-like understanding of
astrophysical concepts. To date, all astronomy LTs have been developed for
undergraduate courses taught in-person. Increases in online course enrollments
and the COVID-19 pandemic further highlighted the need for additional
interactive, research-based, curricular materials designed for online
classrooms. To this end, we developed and assessed the efficacy of an
innovative, interactive LT designed to teach planet formation in asynchronous,
online, introductory astronomy courses for undergraduates. We utilized the
Planet Formation Concept Inventory to compare learning outcomes between courses
that implemented the new online, interactive LT, and those that used either a
lecture-only approach or utilized a standard pencil-and-paper LT on the same
topic. Overall, learning gains from the standard pencil-and-paper LT were
statistically indistinguishable from the in-person implementation of the online
LT and both of these conditions outperformed the lecture-only condition.
However, when implemented asynchronously, learning gains from the online LT
were lower and not significantly above the lecture-only condition. While
improvements can be made to improve the online LT in the future, the current
discipline ideas still outperform traditional lecture, and can be used as a
tool to teach planet formation effectively.
