This paper presents the results of a study with undergraduate students about dream incubation and problem solving. Dream incubation is the process of intending to have a dream about something. Traditionally, people would intend to have a dream of healing, insight, or transformation, for example, in the ancient Greek healing temples of the dream god Asclepius.
While this study acknowledges its sample is not representative, it does confirm that problems may be solved through dream incubation. Barrett went on to write a great book on the subject.