In Simons and Chabris' (1999) study on visual inattention, researchers standardised the video clips to maintain internal validity.
Explain how the presentation of the unexpected event (the gorilla or the umbrella woman) was controlled to standardise the procedure for all participants.
33 exam-style questions on OCR A Level Psychology Attention, covering Moray (1959): Auditory attention and Simons and Chabris (1999): Visual inattention. Each one has a worked solution and a mark scheme showing where the marks go.