Williams et al wanted to assess the bizarreness in dreams and fantasises. He did this to show support of the activation-synthesis hypothesis of dreaming
They used a natural experiment, with a self-report method. Dreams and fantasises were the IV. There were 12 subjects, most (10) were female.
Participants kept a written journal of their dreams, and judges rated how bizarre they were. Judges had high inter-rater reliability. There was a significant difference between scores given for dreams and fantasies. It showed that: -- Dreams and fantasies are easily told apart -- Particular brain activity in REM sleep is associated with more bizarre dreams -- Parts of the brain become sensorially disconnected and fire randomly