Is the conflict of the wave internal or external?

Conflict found in the novel, The Wave, are both external and internal. The experiment itself is implemented for the sole purpose of engaging students and teaching a specific lesson. Thus, Mr. Ross, internally struggles with the need to engage his students, and uses an experiment that engages their minds, as well as their physical actions. The students actions are physical, the manipulation is internal.

The external problems..... students getting carried away with their roles.... is an external conflict, which requires thought and the ability to control impulses.