SOCI 332 WEEKLY ASSIGNMENT 5
Enter your answers by highlighting or bolding the correct answer. Save
the file using your last name as the beginning of the file name (e.g.,Krieger_SOCI332_Weekly Assignment 5.doc) and submit via “Assignments.” When appropriate,
show your work. You can do the work by hand, scan/take a digital
picture, and attach that file with your work.
For
the following question(s): A school counselor tests the level of depression in
fourth graders in a particular class of 20 students. The counselor wants to
know whether the kind of students in this class differs from that of fourth
graders in general at her school. On the test, a score of 10 indicates severe
depression, while a score of 0 indicates no depression. From reports, she is able
to find out about past testing. Fourth graders at her school usually score 5 on
the scale, but the variation is not known. Her sample of 20 fifth graders has a
mean depression score of 4.4. Use the .01 level of significance.
1. The counselor calculates the unbiased
estimate of the population’s variance to be 15. What is the variance of the
distribution of means?
A) 15/20 = 0.75
B) 15/19 = 0.79
C) 152/20 = 11.25
D) 152/19 = 11.84
2.
Suppose the counselor tested the null
hypothesis that fourth graders in this class were less depressed than those at the
school generally. She figures her t score to be–.20.
What decision should she make regarding the null hypothesis?
A) Reject it
B) Fail to reject it
C) Postpone any decisions until a more conclusive
study could be conducted
D) There is not enough information given to make
a decision
3.
Suppose the standard deviation she
figures (the square root of the unbiased estimate of the population variance)
is .85. What is the effect size?
A) 5/.85 = 5.88
B) .85/5 = .17
C) (5–
4.4)/.85 = .71
D) .85/(5–
4.4) = 1.42
For
the following question(s): Professor Juarez thinks the students in her
statistics class this term are more creative than most students at this
university. A previous study found that students at this university had a mean
score of 35 on a standard creativity test. Professor Juarez finds that her
class scores an average of 40 on this scale, with an estimated population
standard deviation of 7. The standard deviation of the distribution of means
comes out to 1.63.
4. What is the t score?
A) (40–
35)/7 = .71
B) (40–
35)/1.63 = 3.07
C) (40–
35)/72= 5/49 = .10
D) (40–
35)/1.632= 5/2.66 = 1.88
5. What effect size did Professor Juarez
find?
A) (40–
35)/7 = .71
B) (40–
35)/1.63 = 3.07
C) (40–
35)/72= 5/49 = .10
D) (40–
35)/1.632= 5/2.66 = 1.88
6. If Professor Juarez had 30 students in her
class, and she wanted to test her hypothesis using the 5% level of
significance, what cutoff t
score would she use? (You should be able to figure this out without a table
because only one answer is in the correct region.)
A) 304.11
B) 1.699
C) –.113
D) –2.500
SPSS ASSIGNMENT (10 Points)
Single Sample & Dependent Samples t Tests
Review the
five steps of hypothesis testing and complete the following problem. Choose one of the problems to
solve belowand
follow the given instructions. Be
sure to cut and past the appropriate result boxes from SPSS under each
problem. All calculations should be
coming from SPSS.
t Test for a Single Sample:
Open SPSS
Enter the number of activities of daily living performed by the depressed
clients studied in #1 in the Data View window.
In the Variable View window, change the variable name to “ADL” and set
the decimals to zero.
Click Analyzeà Compare Meansà One-Sample T testà the arrow to move “ADL” to the Variable(s) window.
Enter the population mean (14) in the “Test Value” box.
Click OK.
1.
Researches are interested in whether depressed people
undergoing group therapy will perform a different number of activities of daily
living after group therapy. The researchers have randomly selected 12 depressed
clients to undergo a 6-week group therapy program.
Use the five
steps of hypothesis testing to determine whether the average number of
activities of daily living (shown below) obtained after therapy is
significantly different from a mean number of activities of 14 that is typical
for depressed people. (Clearly indicate each step).
Test the
difference at the .05 level of significance and, for practice, at the .01 level
(in SPSS this means you change the “confidence level” from 95% to 99%).
In Step 2, show
all calculations.
As part of Step
5, indicate whether the behavioral scientists should recommend group therapy
for all depressed people based on evaluation of the null hypothesis at both
levels of significance and calculate the effect size.
|
CLIENT |
AFTER THERAPY |
|
A |
17 |
|
B |
15 |
|
C |
12 |
|
D |
21 |
|
E |
16 |
|
F |
18 |
|
G |
17 |
|
H |
14 |
|
I |
13 |
|
J |
15 |
|
K |
12 |
|
L |
19 |
t
Test for Dependent Means:
Open SPSS
Enter the number of activities of daily living performed by the depressed
clients studied in Problem 2 in the Data View window. Be sure to enter the
“before therapy” scores in the first column and the “after therapy” scores in
the second column.
In the Variable View window, change the variable name for the first
variable to “ADLPRE” and the variable name for the second variable to
“ADLPOST”. Set the decimals for both variables to zero.
Click Analyzeà Compare MeansàPaired-Samples T Testàthe arrow to move “ADLPRE” to the Paired Variable(s)
windowà “ADLPOST” and then click the arrow to move the
variable to the Paired Variable(s) window.
Click OK.
2.
Researchers are interested in whether depressed people
undergoing group therapy will perform a different number of activities of daily
living before and after group therapy. The researchers have randomly selected 8
depressed clients in a 6-week group therapy program.
Use the five
steps of hypothesis testing to determine whether the observed differences in
numbers of activities of daily living (shown below) obtained before and after
therapy are statistically significant at the .05 level of significance and, for
practice, at the .01 level. (Clearly indicate each step).
In Step 2, show
all calculations. As part of Step 5, indicate whether the researchers should
recommend group therapy for all depressed people based on evaluation of the
null hypothesis at both levels of significance and calculate the effect size.
|
CLIENT |
BEFORE THERAPY |
AFTER THERAPY |
|
A |
12 |
17 |
|
B |
7 |
15 |
|
C |
10 |
12 |
|
D |
13 |
21 |
|
E |
9 |
16 |
|
F |
8 |
18 |
|
G |
14 |
17 |
|
H |
11 |
8 |
Submit the following files to the
Drop Box no later than Sunday of Week 5:
üWord file
(this file) saved as Krieger_SOCI332_Weekly
Assignment 5.doc
üSPSS
output file (.spv) saved as Krieger_SPSS-week5_output
The deadline for this assignment
is 11:59 PM EST on Sunday of Week 5
