Why do the editors of psychology journals sometimes insist that psychologists include an estimate of effect size along with the probability statistic when they report a significant result?
A) By itself, a probability statistic indicates only whether the difference in means between the groups in the study is unlikely to reflect chance. The effect size statistic indicates whether the difference is large.
B) By itself, a probability statistic indicates only that the difference in means between the groups in the study is large. The effect size statistic indicates whether the difference is unlikely to reflect chance.
C) The effect size statistic replicates the probability statistic, providing additional evidence that the result is significant.
D) By itself, a probability statistic indicates only that there is a relationship between two variables. The effect size statistic gives some indication of cause and effect.

Question

Quizplus · Accepted Answer

Including an estimate of effect size along with the probability statistic when reporting a significant result can provide additional information about the magnitude of the effect. A probability statistic by itself only indicates the likelihood that the difference between means is not due to chance, whereas an effect size statistic provides information about the size of the difference, which can be important for interpreting the practical significance of the result.

Why Do the Editors of Psychology Journals Sometimes Insist That