Charles has developed a new advertisement that can be used online. He tests how well it draws people's attention by closely
monitoring the eye movement of 1,000 test subjects as the new ad appears on their computer screens!
Charles finds that 97% of the test subjects' eyes were drawn toward the ad when it appeared. By comparison, only 50% of the test
subjects' eyes were drawn toward a box of plain text when it appeared instead. He concludes that the new ads are better at
attracting people's attention than old ads.
What is wrong with Charles' experiment?