Carryover Effects (1 of 4)
A carryover effect is an effect that "carries over" from one
experimental condition to another. Whenever subjects perform in more
than one condition (as they do in
within-subject designs) there is a possibility of carryover
effects. For example, consider an experiment on the effect of rate of
presentation on memory. Subjects are presented with a list of words
and asked to recall as many words as they can. In one condition, the
words are presented one word per second; in the other condition, the
words are presented two words per second. The question is whether or
not having performed in one condition affects performance in the
second condition. Perhaps learning the first list of words will
interfere with learning the second list because it will be hard to
remember which words were in each list. Or maybe the practice
involved learning one list will make it easier to learn a second
list. In either case, there would be a carryover effect: performance
on the second list would be affected by the experience of being given
the first list.