Psych 541 Quiz 5-If SST = 56 and SSB = 14, SSW
Psych 541 Quiz 5 Summer 2017 47 points
1. If SST = 56 and SSB = 14, SSW = _________.
a. 34
b. 6
c. -6
d. 42
2. If dfB = 4 and dfW = 20, using alpha = 0.05, Fcrit = _________.
a. 2.87
b. 3.10
c. 3.74
d. 6.22
3. An investigator conducts an experiment involving the effects of three levels of a drug on
memory. Subjects are randomly assigned to one of three conditions. A different drug level is
administered in each condition. Memory is measured 10 minutes after each subject
receives the drug. The following scores are recorded. The higher the score, the better the
memory.
Drug Level one
6
5
8
2 two
9
7
9
13 three
14
13
15
19 After conducting a one-way ANOVA of the above data, which of the following is the
variability among the group means _________.
a.
b.
c.
d. 6.50
15.5
100.75
201.5 4. Refer to the drug study. After conducting a one-way ANOVA of the above data, which of
the following is the average variance within each of the three groups.
a. 6.50
b. 15.5
c. 100.75
d. 201.5 5. Refer to the drug study. After conducting a one-way ANOVA of the above data, which of
the following is the F critical using alpha at .05.
a. 3.63
b. 4.26
c. 5.12
d. 4.46
6. If I have four groups, and a total of 40 subjects in the entire experiment, how many within
groups degrees of freedom do I have.
a. 39
b. 3
c. 36
d. 28 7. Refer to the drug study. When calculating the total sum of squares, I utilize the following
expression: SStotal = 1460 – (120)2/12 which equals 260. The SS between = (21) 2/4 +
(38)2/4 + (61)2/4 – (120)2/12 which equals 201.5. Based on this information which of the
following is the numerator of the average variance within each group.
a. 1460
b. 201.5
c. 120
d. 58.5
8. Refer to the drug study. When calculating the total sum of squares, I utilize the following
expression: SStotal = 1460 – (120)2/12 which equals 260. The SS between = (21) 2 + (38)2 +
(61)2 – (120)2/12 which equals 201.5. Based on this information which of the following is the
numerator of the total variance among all the scores.
a. 1460
b. 201.5
c. 120
d. 260. 9. Refer to the drug study Estimate the size of the effect. Using omega squared.
a. 0.5109
b. 0.6698
c. 1.6633
d. 0.7073 10. Refer to drug study. Estimate the size of the effect using Cohen’s f.
a. 1.4244
b. 0.6698
c. 1.6633
d. 1.5546
11. (12 points) In the space below conduct pairwise comparisons using the Tukey, Neuman Keuls,
LSD and Bonferroni for the drug study above. Place the work for each test (show all work) below
the label for each test and be specific when you state you conclusions.
(3 points) Tukey test (show all work for Tukey below) (3 points) Neuman Keuls (show all work for Neuman Keuls below) ( 3 points) LSD (show all work for LSD below) (3 points) Bonferroni (show all work for Bonferroni below) 11. A sleep researcher conducts an experiment to determine whether sleep loss affects the
ability to maintain sustained attention. Fifteen individuals are randomly divided into the
following three groups of 5 subjects each: group 1, which gets the normal amount of sleep
(7-8 hours); group 2, which is sleep-deprived for 24 hours; group 3, which is sleep-deprived
for 48 hour. And group 4 which is sleep deprived for 72 hours. All four groups are tested on
same auditory vigilance task. Subjects are presented with half-second tones spaced at
irregular intervals over a 1-hour duration. Occasionally, one of the tones is slightly shorter
than the rest. The subject’s task is to detect the shorter tones. The following percentages
of correct detections were observed:
Normal Sleep-Deprived
Sleep
for 24 Hours
85
60
83
58
76
76
64
52
75
63 Sleep-Deprived Sleep Deprived
for 48 Hours
for 72 Hours
60
55
48
47
38
27
47
41
50
43 After conducting a one way ANOVA, which of the following is the SSBetween?
a. 3422.4
b. 2234.4
c. 96.555
d. 1953.3
12. Refer to the sleep study. SSW = _________. a. 3422.4
b. 2234.4
c. 96.555
d. 1256.4
13. Refer to the sleep study. Fobt = _________.
a.
b.
c.
d. 20.99
10.99
14.528
3.24 14. Refer to the sleep study. Based on the F obtained which of the following below is the amount of
variability among the means expected by chance.
a. 1140.8
b. 78.525
c. 3422
d. 3255
15.Refer to the sleep study. Using aplha = 0.05, Fcrit = _________.
a. 4.33
b. 3.63
c. 2.96
d. 3.24
16.
a.
b.
c.
d. Refer to the sleep study. Using alpha = 0.05, what do you conclude?
reject H0; sleep deprivation has the same effect on vigilance at all levels
reject H0; sleep deprivation does not have the same effect on vigilance at all levels
retain H0; we cannot conclude that sleep deprivation influences vigilance
accept H0; sleep deprivation has the same effect on vigilance at all levels 17. Refer to sleep study Estimate the size of the effect. Using omega squared.
a. 0.5109
b. 0.6698
c. 1.6633
d. 0..5678
18. Refer to sleep study. Estimate the size of the effect using Cohen’s f.
a. 1.4244
b. 0.6698
c. 1.6633
d. 0.5678 19. If the variability of the cell means around the grand mean is no greater than you would
expect by chance, then you would expect your F ratio to be equal to ?
a. 10
b. 0
c. 2.34
d. 1.00
20. Which of the following would cause F obtained to increase?
a.
b.
c.
d.
e. an increase in the difference between the means
an increase in the within-groups variability
an increase in the magnitude of the independent variable’s effect
a and b
a and c 21. Which of the following assumptions of the analysis of variance if violated is especially
problematic if you have unequal sample sizes.
a. normality
b. homogeneity of variance
c. independence
d. odd numbers
22. The F ratio increases as _________.
a. the variability between means increases relative to the variability within groups
b. the variability between means decreases relative to the variability within groups
c. the total variability increases
d. the total variability decreases
e. the variability within groups remains the same
23. Which of the follow will result if you violate the assumptions of the F test, especially if
you have heterogeneity of variance and unequal n?
a)
b)
c)
d) Power will decrease
Probability of a type 2 error will increase
Probability of a type 1 error will increase
The world will end 24.(12 points) In the space below conduct pairwise comparisons using the Tukey, Neuman
Keuls, LSD and Bonferroni for the sleep study above. Place the work for each test (show all work)
below the label for each test and be specific when you state you conclusions.
(3 points) Tukey test (show all work for Tukey below) (3 points) Neuman Keuls (show all work for Neuman Keuls below) (3 points) LSD (show all work for LSD below) (3 points)
