One way to probe students' misconceptions about science during instruction is by using formative assessments. Described as assessments "for" learning rather than assessments "of" learning (Black and Wiliam 1998), they provide teachers with information about student understanding during instruction. Examples of formative assessments include questions, drawings, and exit slips (see Keeley, Eberle, and Farrin 2005; Keeley 2008; TrauthNare and Buck 2011). This article describes a Role, Audience, Format, and Topic (RAFT) creative writing assignment that formatively assesses high school students' learning in a physical science class focusing on motion. The RAFT writing strategy gives students a writing prompt that requires them to explain a scientific concept in a creative context by considering various perspectives. The RAFT writing prompt engages students in an exploration of a specific topic or concept, while simultaneously allowing them to demonstrate what they know and how they think about the topic.