21. Payne (2001) gave participants a computerized task in which they first see a face and then a picture of either a gun or a tool. The task was to press one button if it was a tool and a different one if it was a gun. Unknown to the participants while they were doing the study, the faces served as a “prime” (something that starts you thinking a particular way) and half the times were of a black person and half the time of a white person. Table 2-8 shows the means and standard deviations for reaction times (time to decide if the picture is of a gun or a tool) after either a black or white prime. (In Experiment 2, participants were told to decide as fast as possible.) Explain the results to a person who has never had a course in statistics. (Be sure to explain some specific numbers as well as the general principle of the mean and standard deviation.)
Since we do not have the table, we can't help. You cannot copy and paste it on the site.
Use the formula for the difference between means.
This helps us to determine whether the difference between means is due solely to chance or if it is really a significant difference. The more unlikely it is to occur by chance, the more likely it is to be a significant difference. Most researchers use the criterion of P = .05 as a cutting point to make that decision. They say that since it is so unlikely to occur by chance, that it is significant. Although they might be wrong 5 times in 100, they are assuming that this is not one of these times.
By replicating the experiment and getting the same significant results repeatedly, this drastically reduces the probability of the results being due solely to chance.
I hope this helps. Thanks for asking.