Exam 13: Interpreting the Strength and Importance of Relationships

Some studies can have sample sizes that are so small that researchers have little likelihood of being able to refute sampling error even with effect sizes that most would agree are substantively or clinically significant.

A Cohen's d of .30 and a correlation coefficient of .30 both signify the same degree of relationship strength.

A statistically significant finding:

According to approximate guidelines for interpreting the strength of effect sizes, a Cohen's d of .55 is considered to be:

Effect-size statistics enable us to compare the effects of different interventions across studies using different types of outcome measures.

A correlation of -.40 indicates that 40 percent of the variation in the dependent variable is explained.

Which of the following statements is true about correlation statistics?

All strong and statistically significant relationships are considered to be substantively significant.

Which of the following is true about effect-size statistics?

The probability of committing a Type II error is one minus statistical power.

If statistical power is .80, then the probability of a Type II error is:

In an evaluation of an intervention that seeks to increase self-esteem scores, the experimental group mean is 40, and the control group mean is 22.The pooled standard deviation is 6.Therefore, Cohen's d equals:

According to approximate guidelines for interpreting the strength of effect sizes, a Pearson's r of .30 is considered to be:

Differences in effect sizes automatically indicate which intervention is more effective or valuable.

If a correlation coefficient equals .30, then:

Clinical significance can refer to the meaningfulness and practical value of the benefits of an intervention for each individual recipient of the evaluated intervention.

Trivial relationships:

If Study A reports a Cohen's d of .60, and Study B reports a correlation coefficient of .60, then:

Each of the three statistical approaches that have been proposed for measuring clinical significance is considered by some to be controversial.

Which of the following statements is/are true about meta-analyses?