After watching this video, consider what conclusions you can draw.



1. External validity questions: Is the difference between how this dog and this cat react to the mat typical of the difference between how cats and dogs react to the mat?  That is, do most cats walk on the mat whereas most dogs avoid the mat?
2. Construct validity questions: Assume that dogs and cats do react differently to the illusion mat. In that case, how should you interpret this "clue"--that the cat runs over the mat and the dog does not? Is the cat braver than the dog?  Is the cat smarter than the dog? Is the cat not looking at the mat? Is the cat looking at the mat but not perceiving the illusion? Is the dog reacting to some smell on the mat? Are there other measures (e.g., heart rate monitors, eye-tracking devices) that could help you narrow down the reason that only cats run over the mat? If so, how could those other measures help you figure out the reason cats and dogs react differently to the mat.