Chapter 9 sample online exam questions:
1. Question: According to your textbook and class discussion, which of the following is
not true at the start of the experiment:
Student Answer:
1. Participants who constitute a random sample are randomly assigned to an
experimental condition.
2. The experimental groups have a number of pre-existing differences.
3. The mean and variance of each group are least-squares, unbiased and consistent
estimates of mu and sigma2.
4. Neither 1 nor 2 are true.
5. All of the above (1, 2, and 3) are true.
2. Question: If we run an experiment properly and the results are a statistically significant
F ratio, we can conclude that:
Student Answer:
1. Members of the population from which the sample is drawn can be expected to
react similarly to the experimental groups.
2. The null hypothesis is false and should be rejected.
3. Both 1 and 2.
4. Neither 1 nor 2.
3. Question: At the beginning of a properly run experiment:
Student Answer:
1. The means of the treatment groups should be far apart.
2. The mean squares within all the groups, if summed, will add up to a quantity
about the same size as the population variance.
3. Each treatment group can be assumed to be representative of the population as a
whole.
4. Only 1 and 3 are true.
5. All of the above (1, 2, and 3) are true.
4. Question: To obtain MSB, you divide the sum of squares between groups by:
Student Answer:
1. n-k
2. k-1
3. n-(k-1)
4. dfREG
5. Question: In correlational research, what kind of relationship can you discover?
Student Answer:
1. linear
2. curvilinear
3. causal
4. only 1 and 2 are correct
5. all of the above
6. Question: A drug company compared three new drugs (LoCho, Hearthealth, and
ArtFree) for cholesterol reduction. Al, Barbara, Chuck, and Donna took LoCho. Al’s
cholesterol went down 41 points, Barbara’s went down 43 points, Chuck’s went down 45
points, and Donna’s 43 points. Ed, Francine, George, and Harriet took Hearthealth. Ed’s
cholesterol went down 46 points, Francine's went down 42 points, George's went down
47 points, and Harriet's 53 points. Ira, Jenny, Karl, and Linda took ArtFree. Ira's
cholesterol went down 50 points, Jenny's went down 47 points, Karl's went down 46
points, and Linda's 49 points.
For an answer to be correct, degrees of freedom, between and within groups and p values
have to be correct. F should be correct to within .10 of the right answer. (This last is to
allow for rounding error.) Which of the following answers is correct?
Student Answer:
1. F(2,9) = 1.15, n.s.
2. F(2,9) = 2.15, n.s.
3. F(2,9) = 3.15, n.s.
4. F(2,9) = 4.15, p<.05
5. None of the above.
7. Question: A researcher compared three types of psychotherapy for Generalized
Anxiety Disorder: Interpersonal Therapy (IPT), Cognitive Behavior Therapy (CBT) and
Mindfulness Therapy (MT). Results were measured with an index of relaxation. Higher
scores equaled greater relaxation. The seven participants in the IPT groups averaged 3.00.
The seven participants in the CBT group averaged 6.00. The seven participants in the MT
group averaged 4.00. The overall mean was 4.33. The sum of squares within group was
72.00.
For an answer to be correct, degrees of freedom, between and within groups and p values
have to be correct. F should be correct to within.10 of the right answer. (This last is to
allow for rounding error.) Which of the following answers is correct?
Student Answer:
1. F(2,18) = 4.08, n.s.
2. F(2,18) = 4.58, p<.05
3. F(2,18) = 5.08, p<.05
4. F(2,18) = 5.58, p<.05
5. None of the above.
8. Question: A researcher compared responses to five doses (placebo, low dose, moderate
dose, moderately high dose, and high dose) of Thinkright, a new drug for schizophrenia.
There were 5 participants in each group. She measures responses on a scale of normal
cognition. Higher scores equal more normal functioning. The sum of squares within
group is 220.00. The sum of squares between groups was 200.00.
For an answer to be correct, degrees of freedom, between and within groups and p values
have to be correct. F should be correct to within .10 of the right answer. (This last is to
allow for rounding error.) Which of the following answers is correct?
Student Answer:
1. F(4,20) = 2.55, n.s.
2. F(4,20) = 3.55, p<.05
3. F(4,20) = 4.55, p<.01
4. F(4,20) = 5.55, p<.01
5. None of the above.
Answers-CH9: 1. The experimental groups have a number of pre-existing differences. 2.
Both 1 and 2. 3. Each treatment group can be assumed to be representative of the
population as a whole. 4. k-1. 5. only 1 and 2 are correct. 6. F(2,9) = 3.15, n.s. 7.
None of the above.
8. F(4,20) = 4.55, p<.01.
Chapter 10 sample online exam questions:
1. Question: You run a two-factor experiment comparing responses to two different doses
of a new antidepressant (placebo vs. active drug dose). Participants are randomly
assigned to also receive one of three forms of psychotherapy (cognitive therapy with
mindfulness training, standard cognitive therapy or supportive psychotherapy) along with
either active drug or placebo. This is a 2x3 design. There are 10 participants in each of
the six groups. How many degrees of freedom are there for MSW?
Student Answer:
1. 30
2. 40
3. 50
4. 60
5. None of the above
2. Question: If Factor 1 is statistically significant, what can we say about Factor 2 and/or
the interaction of the two variables:
Student Answer:
1. Factor 2 is almost certainly significant as well.
2. Factor 2 is probably significant as well.
3. The interaction of Factors 1 and 2 is almost certainly significant as well.
4. The interaction of Factors 1 and 2 is probably significant as well.
5. There is no way to know about the main effect of Factor 2 or the interaction of
Factors 1 and 2.
3. Question: According to your textbook and class discussion, a key element at the start
of the experiment is that:
Student Answer:
1. participants, who constitute a random sample, select their own experimental group
2. the experimental groups are different from each other on all pre-existing
differences
3. the mean and variance of each and every experimental group is a least-squares,
unbiased and consistent estimate of mu and sigma on every measure
4. Only 1 and 2 are true
5. All of the above (1, 2, and 3) are true
4. Question: You run a two-factor experiment comparing responses to 4 doses of a new
antidepressant (placebo, low, moderate and high doses). Participants are randomly
assigned to also receive one of three forms of psychotherapy (cognitive therapy with
mindfulness training, standard cognitive therapy or supportive psychotherapy) along with
either active drug or placebo. This is a 4x3 design. There are 6 participants in each of the
twelve groups? How many degrees of freedom are there for MSF2, the type of
psychotherapy they received?
Student Answer:
1. 2
2. 4
3. 6
4. 8
5. None of the above
5. Question: You run a two-factor experiment comparing responses to 3 doses of a new
antidepressant (placebo, moderate and high doses). Participants are randomly assigned to
also receive one of three forms of psychotherapy (cognitive therapy with mindfulness
training, standard cognitive therapy or supportive psychotherapy) along with either active
drug or placebo. This is a 3x3 design. There are 6 participants in each of the nine groups?
How many degrees of freedom are there for MSINT?
Student Answer:
1. 2
2. 4
3. 6
4. 18
5. None of the above
6. Question: In a study of patients with Generalized Anxiety Disorder, a drug company
compared the effect of a new antianxiety drug (Noshakes) and Cognitive Behavioral
Therapy in a 2 (Placebo vs. Noshakes) x 2 (Supportive Discussion Group vs. CBT)
design. There were 4 participants in each group. Al, Barbara, Chuck, and Donna got the
two placebos (Placebo Drug and Supportive Discussion ). Al’s anxiety went down 14
points, Barbara’s went down 13 points, Chuck’s went down 16 points and Donna’s 9
points. Ed, Francine, George, and Harriet got Placebo Drug plus CBT. Ed’s anxiety went
down 11 points, Francine’s went down 7 points, George’s went down 6 points and
Harriet’s 4 points. Ira, Jenny, Karl, and Linda got Noshakes plus the Supportive
Discussion Group). Ira’s anxiety went down 13 points, Jenny’s went down 12 points,
Karl’s went down 14 points and Linda’s 21 points. Martin, Nancy, Oscar, and Pat got
Noshakes and CBT) Martin’s anxiety decreased 18 points, Nancy’s went down 30 points,
Oscar’s went down 36 points, and Pat’s went down 32 points.
To be correct, degrees of freedom, between and within groups and p values have to be
correct. F should be correct to within .10 of the right answer. (This last is to allow for
rounding error.) Which of the following is the correct F for the interaction of Drug and
Psychotherapy?
Student Answer:
1. F (3, 12) = 5.35, significant
2. F (1, 15) = 20.08, significant
3. F (1, 12) = 17.02, significant
4. F (3, 15) = 6.68, significant
5. None of the above
7. Question: Using a 2x2 design, a researcher compared two types of psychotherapy for
Generalized Anxiety Disorder: Interpersonal Therapy (IPT) and Cognitive Behavior
Therapy (CBT). Additionally half the participants in each form of psychotherapy got a
daily dose of Klonopin (an anti-anxiety medication) or placebo. There were 6 participants
in each of the four groups. Results were measured with an index of relaxation. Higher
scores equaled greater relaxation. Participants in the IPT/placebo group averaged 22.
Participants in the IPT/Klonopin group averaged 26. Participants in the CBT/placebo
group averaged 26. Participants in the CBT/Klonopin group averaged 42. The sum of
squares within group is 800. The overall mean is 29.
To be correct, degrees of freedom, between and within groups and p values have to be
correct. F should be correct to within .10 of the right answer. (This last is to allow for
rounding error.) Which of the following is the correct F for the interaction of Drug and
Psychotherapy?
Student Answer:
1. F (1, 20) = 5.40 p<=.05
2. F (3, 20) = 0.30 n.s.
3. F (1, 23) = 1.04 n.s.
4. F (1, 20) = 0.90 n.s.
5. None of the above
8. Question: Using a 2x4 design, a researcher compared responses to two forms of
psychotherapy (CBT vs. IPT) combined with one of four doses (placebo, low dose,
moderate dose, high dose) of Thinkright, a new drug for schizophrenia. There were 4
participants in each group. She measures responses on a scale of normal cognition.
Higher scores equal more normal functioning. The sum of squares within group was
780.00. The sum of squares between groups was 600.00. The sum of squares for type of
psychotherapy (CBT vs. IPT) was 220.00. The sum of squares for the interaction of
psychotherapy and drug dose was 80.00.
To be correct, degrees of freedom, between and within groups and p values have to be
correct. F should be correct to within .10 of the right answer. (This last is to allow for
rounding error.) Which of the following is the correct F for the main effect of Drug dose?
Student Answer:
1. F(3, 24) = 3.08 p<= .05
2. F(7, 24) = 1.32 n.s.
3. F(4, 24) = 2.31 p<= .05
4. F(3, 24) = 3.08 p<= .01
5. None of the above
Answers-CH10: 1. None of the above. 2. There is no way to know about the main effect
of Factor 2 or the interaction of Factors 1 and 2. 3. the mean and variance of each and
every experimental group is a least-squares, unbiased and consistent estimate of mu and
sigma on every measure. 4. 2. 5. 4. 6. F (1, 12) = 17.02, significant. 7. F (1, 20) =
5.40 p<=.05.
8. F(3, 24) = 3.08 p<= .05.