use proper grammar and punctuation in your responses.
Turn-in: (2) SPSS output please and copy charts into a Windows word
DATA ANALYSIS SECTION
1. Neighbors have been complaining about the residences of the T Home for Retired Statisticians. It seems that the retirees have taken to shouting obscenities at passersby. Dr. Je
y Atric, Chief Psychologist at the home, has decided to try a system of fines - taking away computer time - to control these outbursts. Retirees were asked to volunteer to participate in an experiment and those agreeing to participate were randomly assigned to four groups. Participants in the first group received no fine (i.e. no loss of computer time) for each outburst. The second group received a fine for 5-minute loss of computer time; group three received a fine of 10 minutes, and group four received a fine of 20 minutes. Dr. Je
y Atric recorded the number of obscene outbursts from each subject during the two weeks following the initiation of this program. Data gathered from this study are given below. Conduct the appropriate statistical tests using an α = .05.
0 minutes
5 minutes
10 minutes
20 minutes
18
19
10
3
19
19
5
8
28
23
10
4
11
9
9
11
19
18
21
8
15
16
13
7
17
16
11
12
(a) What are the independent and dependent variables in this scenario? (2 points)
(b) What was the purpose of random assignment in this study? (1 point)
(c) One of the first things to do in the analysis of your data is to check to see if the data meet the assumptions for the use of the statistical method. What assumption would you want to test for this scenario? Was this assumption met for these data? What specific information on the printout did you use to come to this conclusion? (3 points)
(d) Is the average number of obscene outbursts the same for the four groups of statisticians? What specific information on the printout did you use to come to this conclusion? (2 point)
(e) What proportion of variance in the number of obscene outbursts can be attributed to differences in the amount of fines received? (3 points)
(f) Use the Tukey procedure to determine which pairs of groups differ. What do these results indicate to us about the effectiveness of the fines in reducing the number of obscene outbursts (i.e., interpret your findings from the Tukey procedure)? (2 point)
(g) Calculate the Cohen’s d effect sizes for the pairwise differences between means found to be significant in the post hoc comparisons. What do these effect sizes represent? That is, how do you interpret them? (3 points)
(h) To whom, if anyone, can we generalize our findings? (2 point)
(i) Why would a second recorder, in addition to Dr. Je
y Atric, be useful in this situation? (1 point)
(j) Give a write-up of the results as you would for a traditional APA-style journal article. (6 points)
2. The administrator at X County General Hospital claims that on weekends the average wait time for emergency room visits is 10 minutes. Based on discussions with friends who complained about how long they waited to be seen in the ER over a weekend, you dispute the administrator's claim. You decide to test your hypothesis. Over the course of a few weekends, you record the wait time for 40 randomly selected patients. The average wait time for these 40 patients is 12.3 minutes with a standard deviation of 3.1 minutes. Based on these data, do you have enough evidence to support your hypothesis that the average ER wait time exceeds 10 minutes? Use a one-tailed test with an α = .05.
a. What is the appropriate parametric statistical test and why is it appropriate? (3 points)
. State your hypotheses (2 point)
c. Give critical value, compute the test statistic, and state your decision. (3 points)
d. Compute the 95% confidence interval for the mean. Comment on what it means. (2 points)
e. Compute the Cohen’s d effect size and substantively interpret the effect size. (2 points)
f. What do you conclude about the average ER wait time at XGeneral? Is the average wait time longer than 10 minutes? (2 point)
g. Give a write-up of the results as you would for a traditional APA-style journal article. (6 points)
3. Sensory isolation chambers are used to examine the effects of mild sensory deprivation. The chamber is a dark, silent tank where subjects float on heavily salted water and are thereby deprived of nearly all external stimulation. Sensory deprivation produces deep relaxation and has been shown to produce temporary increases in sensitivity for vision, hearing, touch, and even taste. A researcher collected data on the hearing threshold for a group of seven subjects who were tested before and immediately after one hour of deprivation. Data for these tests are given below where a lower score indicates more sensitive hearing. Do these data indicate that deprivation has a significant effect on hearing threshold? Use an alpha of .05.
Before
31.2
31.9
32.6
34.5
30.9
29.7
34.4
Afte
29.0
29.7
32.3
31.5
31.1
29.2
32.5
(a) What is the appropriate parametric statistical test and explain why? (3 points)
(b) Do these data indicate that deprivation has a statistically significant effect on hearing threshold? If so, what was the effect? Give the statistics that you used to come to these conclusions. (2 points)
(c) Give a write-up of the results as you would for a traditional APA-style journal article. (6 points)
(d) What alternative non-parametric test could have been used? Which do you think is most appropriate in this situation, the parametric or non-parametric test, and why? (3 points)
4. A developmental psychologist wants to test the extent to which birth order predicts the amount of attention a child receives from his or her parents. The psychologist records the time, in minutes, those parents spend with their child during a 20-minute session. All children are the same age at the time of the test. The data for the 14 participants are below. Use an alpha of .05 to answer the questions below.
Birth Orde
1
1
5
2
3
2
4
4
2
1
3
1
2
3
Time attending to child
12
13
8
10
15
15
8
8
8
10
9
11
12
9
(a) Graph these data using a scatterplot. What does the scatterplot indicate about the relationship? (2 points)
(b) What is the Pearson r & Spearman rho co
elations between birth order and the amount of time parents spent attending to their child? Which co
elation, Pearson or Spearman, would be most appropriate to use in this situation and why? (3 points)
(c) What is the regression equation used to predict time spend attending to child from birth order? (3 points)
(d) What is the coefficient of determination for this relationship? What does it mean? (3 points)
(e) Emily is a first-born child, what is the predicted amount of time spent attending to her? If her parents actually spent 12 minutes attending to her, what is the e
or of prediction for Emily’s time? (3 points)
(f) Give a write-up of the results as you would for a traditional APA-style journal article. (6 points)
5. A researcher wants to determine whether children will learn concepts better with positive examples alone or with both positive and negative ones. Ten children are randomly assigned to each of the two experimental conditions; their scores on the concept-formation task are given below (higher scores equal better concept-formation). Decide whether there is a statistically significant difference between the two methods. Use an alpha of .01.
Positive
Positive + Negative
7
14
11
7
7
8
12
11
7
12
9
9
10
13
13
12
6
9
12
9
a. What is the appropriate parametric statistical test and why? (3 point)
. Do you meet the assumptions underlying this statistical test? Give the statistics that tell you this information. (3 points)
c. Did the children with only positive examples learn concepts better than those with both positive and negative examples? What specific information did you use to come to this conclusion? (3 points)
d. Calculate the Cohen’s d effect size and omega-squared effect size. Comment on what they mean. (3 points)
e. Give an appropriate 99% confidence interval for the population mean. Comment on what it means. (3 points)
f. Give a write-up if the results as you would for a traditional APA-style journal article. (6 points)
SHORT ANSWER SECTION
1. Identify the relationship between variables X and Y that are demonstrated in the following scatterplots: (1 points each)
a. XXXXXXXXXXb.
c. XXXXXXXXXXd.
2. Which of following are more likely to lead to the rejection of the null hypothesis? (1 point each)
(a) A one-tailed test or a two-tailed test
(b) A .05 level of significance or .01 level of significance
(c) A sample size of 144 (n = 144) or a sample size of 444 (n = 444)
3. Identify each of the following e
ors. That is for each situation described indicate what kind of statistical e
or it represents, if any. (1 points each)
(a) Based on an independent-samples t-test you conclude that the mean for Group A in the population is higher than the mean for Group B when in fact the two sample means come from the same population.
(b) Based on a z-test, you conclude that the null hypothesis is false when the mean for Group A in the population is higher than the mean for Group B.
(c) You conclude that the difference in two sample means is small enough so that it might represent a difference of zero in the population. The real difference in the population is one.
4. Explain why three different measures of central tendency are necessary. Why isn’t one standard procedure sufficient? (2 points)
5. Why is a 99% confidence interval wider than a 95% confidence interval? When you construct a 95% confidence interval, what are you 95% confident about? (2 points)
6. A significance test is performed and p