Sara decides to use the number of times the camera is turned off during lessons as a measure of whether Sean can follow teacher instructions. She assumes that the number of times that the camera is turned off is indicative of the number of times that he seeks assistance from his mother. Is this an accurate assumption? Although an imperfect measure, is this a reasonable measure, given the difficulties in obtaining data in virtual environments? Are there other ways that she could have obtained this information (without adding to the burden of Mrs. Jackson during home instruction)? (D1, D7)