Data from a large-scale study show that the mean score on the Cognitive Reflection Task is μ0 = 1.15 when the test materials are printed in normal font. A random sample of 81 participants completed the task when the test materials were presented in a hard to read font; their mean performance was m = .94. The difference between 1.15 and .94 corresponded to tobs = –1.22. What is the estimated effect size?
0.02
–0.14
11.00
–0.02
