Question 1 of 25 
1.0 Points 
Effect size is a measure of:
A.the difference
between individual members of a sample 
 B.the extent to which
two populations overlap 
 C.the extent to which
two populations do not overlap 
 D.the statistical
significance of a research study 

Reset Selection 
Question 2 of 25 
1.0 Points 
Which of the following is NOT a correct statement about effect size of a study
finding:
A.It provides much
information about statistical significance. 
 B.It is a standardized
measure of lack of overlap between populations. 
 C.It increases with
greater differences between means. 
 D.It can be converted
to a standardized effect size. 

Reset Selection 
Question 3 of 25 
1.0 Points 
According to Cohen’s conventions, for research that compares means, a large
effect size in which only about 53% of the populations of individuals overlap
would be:

Question 4 of 25 
1.0 Points 
Some IQ tests have a standard deviation of 16 points. If an experimental
procedure produced an increase of 3.2 IQ points, the effect size would represent
a __________ effect size.

Question 5 of 25 
1.0 Points 
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.
A.small 
 B.medium 
 C.large 
 D.unable to determine
without additional information 

Reset Selection 
Question 6 of 25 
1.0 Points 
In what way is effect size most comparable to a Z score?
A.It can range from
1 to +1 
 B.It provides a
direct indication of statistical significance 
 C.It provides a
standard for comparison for results across studies, even studies using different
measures 
 D.All of the
above 

Reset Selection 
Question 7 of 25 
1.0 Points 
Cohen has proposed some effectsize conventions based on the effects observed in
psychology research in general because:
A.researchers
frequently need to decide whether the effect size that they have found allows
them to reject the null hypothesis 
 B.it is usually
difficult to know how big an effect to expect from a given
experiment 
 C.Cohen originally
developed the relevant scales 
 D.they are more
accurate than figuring a minimum meaningful difference 

Reset Selection 
Question 8 of 25 
1.0 Points 
The effect size conventions proposed by Cohen are useful to researchers for:
A.predicting the
value of the measured variable to use for the experimental
condition 
 B.evaluating research
results to determine if they are statistically significant 
 C.predicting the
effect of a study on various populations 
 D.determining the
power of a planned study 

Reset Selection 
Question 9 of 25 
1.0 Points 
A statistical method for combining effect sizes from different studies is known
as:
A.combination
analysis 
 B.comparison
analysis 
 C.multivariate
analysis 

D.metaanalysis 

Reset Selection 
Question 10 of 25 
1.0 Points 
Reviews of a collection of studies on a particular topic that use metaanalyses
represent an alternative to traditional __________ articles. These traditional
articles describe and evaluate each study and then attempt to draw some overall
conclusion.
A.general educational
method 
 B.computerassisted
research 
 C.engagement goal
setting 
 D.narrative
literature review 

Reset Selection 
Question 11 of 25 
1.0 Points 
It is useful to understand statistical power for which of the following reasons?
A.Determining the
number of participants to use in an experiment 
 B.Making sense of
findings in research articles 
 C.Understanding the
implications of a study that is not statistically significant 
 D.All of the
above 

Reset Selection 
Question 12 of 25 
1.0 Points 
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.”

Question 13 of 25 
1.0 Points 
When a study has only a small chance of being significant even if the research
hypothesis is true, the study is said to have:
A.low
power 
 B.low
probability 
 C.low market
value 
 D.low sample
size 

Reset Selection 
Question 14 of 25 
1.0 Points 
Standard power tables are useful for:
A.directly
determining the power of an experiment 
 B.determining the
predicted score (but not the variance) for the group exposed to the experimental
manipulation 
 C.determining the
predicted effect size of a proposed experiment 
 D.determining the
probability of falsely accepting the research hypothesis 

Reset Selection 
Question 15 of 25 
1.0 Points 
Effect size is one of the two major factors that contribute to power. Another
factor is:
A.the sample’s
standard deviation 
 B.the minimum
meaningful difference 
 C.the sample
size 
 D.the mean of the
known population 

Reset Selection 
Question 16 of 25 
1.0 Points 
A researcher may not be able to change the effect size of a planned study to
increase power. Another aspect of a planned study that the researcher can
usually change to increase power is:
A.the sample
size 
 B.the beta
level 
 C.the population
parameters 
 D.the sample
mean 

Reset Selection 
Question 17 of 25 
1.0 Points 
In actual practice, the usual reason for determining power before conducting a
study is to:
A.eliminate the
possibility that a mistake may occur 
 B.ensure that
regardless of whether the research hypothesis is true, the experiment will yield
a significant result 
 C.determine the
number of participants needed to have a reasonable chance of getting a
significant result if the research hypothesis is true 
 D.recognize the
likelihood that the experiment will need to be repeated 

Reset Selection 
Question 18 of 25 
1.0 Points 
What effect will using a onetailed test over a twotailed test have on power
(presuming the true population difference is in the expected direction)?
A.it will increase
power 
 B.it will have no
effect on power 
 C.it will decrease
power 
 D.power cannot be
calculated if a onetailed test is used 

Reset Selection 
Question 19 of 25 
1.0 Points 
Using a twotailed test makes it __________ to get significance on any one tail.
Thus, keeping everything else the same, power __________ with a twotailed test
than with a onetailed test.
A.easier;
more 
 B.harder;
less 
 C.easier;
less 
 D.harder;
more 

Reset Selection 
Question 20 of 25 
1.0 Points 
If the research hypothesis is true, but the study has a low level of power:
A.there is a high
probability that the study will have a significant result 
 B.the probability of
getting a significant result is low 
 C.the null hypothesis
will almost certainly be rejected 
 D.the significance
level selected is probably too lenient (for example, .10 instead of
.05) 

Reset Selection 
Question 21 of 25 
1.0 Points 
Practical significance is a combination of statistical significance and:
A.effect
size 
 B.the level of
measurement (whether it is equal interval or ordinal) 
 C.the population
parameters 
 D.the amount over or
under that level that the sample scored 

Reset Selection 
Question 22 of 25 
1.0 Points 
In statistics, we cannot state that the research hypothesis is ever definitely
false. However, if one fails to reject the null hypothesis in a study with a
high level of power, this allows us to:
A.suspect that the
research hypothesis may still be true 
 B.conclude that the
research hypothesis is most likely false 
 C.make no statements
about the research hypothesis 
 D.reject the notion
that the effect size has anything to do with statistical
significance 

Reset Selection 
Question 23 of 25 
1.0 Points 
What is the most likely explanation for why a study with a very small effect
size came out significant?
A.the study had a
large sample size 
 B.the study had a
large population standard deviation 
 C.the researcher used
an insensitive hypothesistesting procedure 
 D.the researcher used
a twotailed test 

Reset Selection 
Question 24 of 25 
1.0 Points 
When judging a study’s results, there are two important questions. They are:
A.How large is the
power and how competent are the researchers? 
 B.How stringent is
the significance level and how small is the effect size? 
 C.Is the result
statistically significant and is the effect size large enough for the results to
be meaningful? 
 D.Is the study
replicable and can we draw conclusions despite not having attained statistical
significance? 

Reset Selection 
Question 25 of 25 
1.0 Points 
If the results of a study are not statistically significant and the sample size
is large, then:
A.the result is very
important 
 B.the result proves
the null hypothesis 
 C.the research
hypothesis is probably false 
 D.the result proves
the research hypothesis 

Reset Selection 