Chapter 4, Section 2, Exercise 065 Finger Tapping and Caffeine The effects of caffeine on the body have been extensively studied. In one experiment 1 , researchers examined whether caffeine increases...

Finger Tapping and Caffeine



The effects of caffeine on the body have been extensively studied. In one experiment¹, researchers examined whether caffeine increases the rate at which people are able to tap their fingers. Twenty students were randomly divided into two groups of 10 students each, with one group receiving caffeinated coffee and one group receiving decaffeinated coffee. The study was double-blind, and after a 2-hour period, each student was tested to measure finger tapping rate (taps per minute). The goal of the experiment was to determine whether caffeine produces an increase in the average tap rate. The finger-tapping rates measured in this experiment are stored inCaffeineTaps. A distribution of differences in means, x¯c-x¯n, for randomization samples from this experiment is given in the figure below.


Let group 1 be the people who have had coffee with caffeine and let group 2 be the people who have had coffee without caffeine.