Question 1
The two properties about a set of measurements of a dependent variable that we are most interested in describing are:
frequency and average.
average and correlation.
central tendency and dispersion.
histograms and polygons.
Question 2
The ________________ is the sum of all the scores divided by the number of scores.
median
mean
mode
standard deviation
Question 3
The generally preferred measure of central tendency is usually the
range
mean
standard deviation
median
Question 4
Which of the following is the most useful descriptive statistic for measuring dispersion?
range
variance
mean deviation
standard deviation
Question 5
The standard deviation is
the square of the variance.
the square root of the variance.
smaller than the mean.
the difference between the highest and lowest scores.
Question 6
If the mean I.Q. is 100 and the standard deviation of I.Q. scores is 15, then an I.Q. of 130 will have a z score (or standard score) of
1.00
0.00
2.00
-2.00
Question 7
Inferential statistics allow you to decide whether a difference between the experimental and the control group is due to _______________ or ________________.
manipulation; chance
manipulation; experimental error
sampling error; independent variable
independent variable; experimental error
Question 8
The null hypothesis suggests that the two samples come from ___________ distribution(s), and the experimental hypothesis suggests that the two samples come from _____________ distribution(s).
different; different
different; the same
the same; different
the same; the same
Question 9
The power of a statistical test refers to its ability to
reject false null hypotheses.
reject false experimental hypotheses.
reject true null hypotheses.
reject true experimental hypotheses.
Question 10
Simple analysis of variance is used in designs having
one independent variable
more than one independent variable
more than one independent variable (IV) but less than four IVs
more than one dependent variable
Question 11
The number of participants in a study is denoted by
s.
n.
z.
r.
Question 12
A _____________ is a complete set of measurements.
sample
population
random sampling
parameter
Question 13
_____________ is one way of ensuring that a sample is representative of the population.
The two-tailed test
The between-subjects design
The sign test
Random sampling
Question 14
If we conduct an experiment on average young, white, college males, inferential statistics allow us to generalize to the population of
average young, white, college males.
college male students.
college students.
young adults.
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Question 15
If we apply an alpha level of .05, and there really is no effect of the experimental manipulation, then one should make
a Type I error
5% of the time.
10% of the time.
15% of the time.
95% of the time.
Question 16
Which of the following would be considered the most conservative alpha level?
.01
.05
.10
.15
Question 17
The prediction that alcohol slows reaction time is
nondirectional.
directional.
semidirectional.
partially directional.
Question 18
Two-tailed tests are _______________ conservative and ______________ powerful than one-tailed tests.
less; less
less; more
more; less
more; more
Question 19
The _____________ indicates the number of scores that are free to vary.
U
degrees of freedom
magnitude of effect
point biserial
Question 20
The ____________ is used to analyze the results when there are more than two groups.
t-test
z-test
analysis of variance
none of the above
Question 21
The __________ maintains that two conditions do not differ.
experimental hypothesis
level of confidence
law of effect
null hypothesis
Question 22
A conservative statistical test is one that
minimizes both Type I and Type II errors.
minimizes Type I errors, but increases the chance of Type II errors.
minimizes Type II errors, but increases the chance of Type I errors.
increases the chance of both Type I and II errors.
Question 23
What are inferential statistics used for?
summarize the mean and standard deviation of the data
estimate if differences between groups are by chance
describe the data from 2 unrelated groups
describe the relationship within a set of data
Question 24
Descriptive statistics are used to:
compare the signficance of the difference between 2 data sets
test the difference between the means
describe the observations
describe the type one error in an experiment
Question 25
Which of the following is not a characteristic of the normal curve:
bell-shaped
represents 100% of the scores under the curve
100 is at the center
allows us to determine rank