In a famous experiment on the unreliability of eyewitness testimony, participants first watched a video of a car wreck and were then asked either, "How fast was the car going when it hit the other car?" or "How fast was the car going when it smashed into the other car?" The hypothesis was that the word "smashed" would induce higher estimates of speed than the word "hit." What is the null hypothesis?
A) The "hit" group will estimate a lower speed than the "smashed" group.
B) Only the "smashed" group will estimate a high speed.
C) Both groups will give similar estimates of speed.
D) Neither group will estimate the speed.

Question

Quizplus · Accepted Answer

The null hypothesis is always that there will be no significant difference between groups or conditions. In this case, the null hypothesis would be that both groups (the "hit" and "smashed" groups) will give similar estimates of speed. This is because the null hypothesis assumes that there is no effect of the wording of the question on participants' estimates of speed.

In a Famous Experiment on the Unreliability of Eyewitness Testimony