A Researcher Reports That the Mean Difference in Response Time

Multiple Choice

A researcher reports that the mean difference in response time to an auditory versus a visual cue is 0.83 s,with a pooled sample variance equal to 2.45.What is the effect size for this test using estimated Cohen's d?

A) d = 0.53; medium effect size
B) d = 0.53; large effect size
C) d = 0.34; small effect size
D) d = 0.34; medium effect size