In the elaborated model of TPACK that we propose here,
TCK refers to a knowledge of the topic-specific representations (RT) in a given content domain that utilize emerging technologies.
While the focus on representations does not fully represent the bidirectional relationship of content and technology,
it does illuminate what we found to be the most practical and widespread form of TCK for teachers—knowledge of how to represent concepts with technology.
The knowledge of these representations exists independent of knowledge about their use in a pedagogical context.
As the technologies used in the representations become mainstream, that knowledge transforms
into content knowledge.
For example, graphing calculators were once considered emerging technologies in mathematics,
but knowledge of how they facilitate mathematical representations is now part of the content of mathematics itself.
Alternatively, software for three-dimensional modeling of numerical data, such as GraphCalc, is an emerging technology.
Knowledge of how it facilitates content representation would be considered TCK, while knowledge of how the traditional graphing calculator facilitates those representations would be CK.