Effect size is intended to provide what?

Effect size is intended to provide what?

• A. The p-value of the observed result.
• B. The variability of scores within groups.
• C. Measurement of the absolute magnitude of a treatment effect, independent of sample size.
• D. The likelihood of replication.

Answer: (C)

Effect size tells you how big the treatment effect actually is, in a way that doesn’t depend on how many people were studied. It expresses the absolute magnitude of the difference or relationship, so you can judge practical significance across studies with different sample sizes. For example, a difference of 0.8 standard deviations (a large effect) means the treatment moved outcomes by a large, interpretable amount, regardless of whether the study had a small or large sample. This is different from a p-value, which reflects statistical significance and can be influenced by sample size. The other concepts describe dispersion within groups or the probability of observing the result again, not the size of the effect itself.

Effect size tells you how big the treatment effect actually is, in a way that doesn’t depend on how many people were studied. It expresses the absolute magnitude of the difference or relationship, so you can judge practical significance across studies with different sample sizes. For example, a difference of 0.8 standard deviations (a large effect) means the treatment moved outcomes by a large, interpretable amount, regardless of whether the study had a small or large sample. This is different from a p-value, which reflects statistical significance and can be influenced by sample size. The other concepts describe dispersion within groups or the probability of observing the result again, not the size of the effect itself.