Final answer:
Lindsey's intervention lacks the dimension of generality in ABA, which ensures the transfer of learned skills to various contexts and stimuli, like recognizing peers from photographs in addition to in-person interactions.
Step-by-step explanation:
In the scenario described, Lindsey, a paraprofessional, is using discrete trial training to teach her student to recognize his classmates by name, which falls under the methods of applied behavior analysis (ABA). Although the student is able to identify his classmates in person, he struggles to do so using two-dimensional photographs. The lack of transfer of learning to different contexts or stimuli suggests that Lindsey's intervention lacks generality. Generality, as a dimension of ABA, ensures that the skills acquired during training are maintained over time, can be performed in different environments, and extend to other behaviors or related tasks. In this case, the student should be able to identify his peers regardless of whether it is through in-person interaction or two-dimensional photographs.