Dynamic visualization in animated mathematics videos I: a classification of didactic roles

In recent years, a multitude of innovative educational videos focusing on mathematics and employing dynamic visualization techniques have emerged on YouTube. This study investigates how creators of such videos aim to teach through dynamic visualizations. From a sample of videos, we develop a classification of didactical roles of dynamic visuals and supporting animation techniques. The classification is constructed through an open coding approach, involving an iterative process of defining, analyzing and refining the codes. Additionally, we conducted an interview with a video creator about the intended roles of dynamic visuals employed in his animations. The classification encompasses the following categories of roles: connect objects, (co)vary objects, dynamic concept visualization, dynamic process visualization, symbol sense, connect to reality, and generalization. These roles are implemented through animation techniques like moving and morphing. The nomenclature of these roles suggests their affiliation with various mathematics education research perspectives, including covariational thinking, concept-process duality, symbol sense, and conversion between registers. The classification serves as a foundational framework for further research into the learning outcome and effectiveness of dynamic visualization in educational mathematics videos.