Exam 7: Making Sense of Statistical Significance: Effect Size and Statistical Power

The __________ of a research study is the probability that it will produce a statistically significant result if the research hypothesis is true.

Standard rules about what to consider a small, medium, and large effect size based on what is typical in behavioral and social science research are known as:

The effect size and the number of participants are two important determinants of:

The effect size conventions proposed by Cohen are useful to researchers for:

A biologist is interested in the effects of cross-species interactions on aggression. He combines the results of many studies to determine an overall average effect size. What statistical procedure should he use?

Having a very small amount of overlap between the distribution of population 2 and the predicted distribution of population 1:

According to Cohen's effect size conventions for mean differences, the following represent small, medium, and large effects, respectively:

In the meta-analysis described in your text (by Eppley, Abrams, and Shear)on the effect of relaxation techniques on anxiety levels, the authors found that:

If the research hypothesis is true, an experiment will automatically yield a significant result. (True or False)

Standard power tables are useful for:

One way to increase the power of a planned study by altering the amount of variance within each of the two distributions is to:

Using a two-tailed test makes it __________ to get significance on any one tail. Thus, keeping everything else the same, power __________ with a two-tailed test than with a one-tailed test.

Our general knowledge of what is a small or a large effect size can help the researcher:

A nonsignificant result from a study with low power is truly inconclusive. However, a nonsignificant result from a study with high power does suggest either that the research hypothesis is false or that there is less of an effect than was predicated when figuring power. (True or False)

Using a two-tailed test makes it harder to get significance on any one tail. Thus, power is less with a two-tailed test than with a one-tailed test. (True or False)

If statistical power for a given research study is .40, one can say that: "Assuming the researcher's prediction is correct, the researcher has a __________ chance of attaining statistically significant results."

A statistical method for combining effect sizes from different studies is known as:

It is useful to understand statistical power for which of the following reasons?

The extent to which an experimental procedure separates the two populations of individual scores in a research study is the:

A standard verbal memory test is known to have a standard deviation of 10 points. If an experimental procedure produced an increase of 8 points, the effect size would represent a __________ effect size.