Answer each of the following questions: (a) Explain the carryover effect with regard to the use of the single-subject design in evaluative research; (b) Is this effect an advantage or a disadvantage to the use of single-subject designs? (c) Identify one situation where this effect is likely to be present or absent.

Question

What will be an ideal response?

Answer 1

Ans: The carryover effect is the possibility of a lasting effect of treatment that is revealed by repeated measurements during a treatment period. Perhaps the effect of treatment is enduring for the client even when the treatment has been completed. Thus, repeated measurements following the termination of treatment may be caused by the carryover effect of the treatment. This means that the ABA design could be problematic because it makes the assumption that treatment is essential to client progress and the second baseline measurements should return to the level of client functioning that was displayed during the first baseline period, and if this does not happen, the interpretation is that the treatment is not effective. Instead, the proper interpretation may be that the effect of the treatment has continued with the client. The carryover effect, therefore, is a disadvantage of some single-subject designs. An example of where the carryover effect is not a problem might be caregiver burden as displayed by the caregiver of a client with dementia. If caregiver support services are withdrawn, it is likely the client’s level of caregiver burden will return to the baseline level. Treatment of a condition like depression or anxiety, however, are expected to carryover, so the carryover effect would be more prominent with this type of example.
Learning Objective: 15-4: Identify which single-subject research designs address maturation as a threat to internal validity.
Cognitive Domain: Comprehension
Answer Location: Carryover Effects From One Time Period to Another
Difficulty Level: Hard