  Teachers in conventional classrooms often ask learners to express themselves
and show their thought processes by speaking out loud, drawing on a whiteboard,
or even using physical objects. Despite the pedagogical value of such
activities, interactive exercises available in most online learning platforms
are constrained to multiple-choice and short answer questions. We introduce
RIMES, a system for easily authoring, recording, and reviewing interactive
multimedia exercises embedded in lecture videos. With RIMES, teachers can
prompt learners to record their responses to an activity using video, audio,
and inking while watching lecture videos. Teachers can then review and interact
with all the learners' responses in an aggregated gallery. We evaluated RIMES
with 19 teachers and 25 students. Teachers created a diverse set of activities
across multiple subjects that tested deep conceptual and procedural knowledge.
Teachers found the exercises useful for capturing students' thought processes,
identifying misconceptions, and engaging students with content.
