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# PART 1: THEORY

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### PART 1: THEORY

1. 1. Exercise 1 Launch SPSS and open the data file Employees.sav. Q1. Calculate frequency tables for the variables Employment Category, Minority Classification and Months since hire. Write down the answers to the following questions: How many managers are there in the sample? ______ What percentage of staff are female? ______ What percentage of staff were hired 72 months ago or less? (Hint: think carefully about which column of the table to use) ______ Q2. Obtain descriptive statistics for variables Current salary and Previous experience (months). In addition to the statistics supplied by default, request the Skewness statistic (this is a measure of asymmetry of the distribution curve) Hint: use the Options... button. Write down the answers to the following questions: What mean value did you obtain for Previous experience? ______ Which of the two variables has the larger value for the skewness statistic? ______ ______ Q3. Perform a crosstabulation of Gender against Minority, requesting that total percentages are included in the cells. Write down the answers to the following questions: How many people are female and belong to a minority? ______ What percentage of people are male and belong to a minority? ______ Q4. Compute a new variable for the Current salary minus Beginning salary (call the new variable saldiff). Compare mean values of saldiff for each Gender. Which Gender has the highest mean saldiff? ______ What is the mean value of saldiff for that group? ______ Q5. Graph Previous experience (months) as a histogram. Before you click on OK, (1) select Display normal curve. and (2) use the Titles button and enter your Name as the title of the graph (it is not sufficient to add these using Microsoft Word later). Paste the figure below and write at least a three-sentence interpretation of the graph.
2. 2. Q1. Recode Educational Level (years) (educ) into a new variable educ18 distinguishing ’18 years or more’ (Range: 18 through Highest) from the rest. When recoding, any missing data should be recoded as system-missing Provide suitable variable and value labels. Now select (filter) cases to include only employees with a Current Salary (salary) of more than \$39999. Find out and write down the answers to the following questions: What percentage of these better paid workers are not "well educated"? ______% What is the maximum Beginning Salary (salbegin) in each of the two educational groups defined by educ18 for these better paid workers? (Hints: Use Option in Compare Means>Means 18+ years \$_____ If necessary edit the pivot table to widen the columns) others \$_____ Q2. IMPORTANT: Remember to select all cases before continuing, via Data=> Select Cases. Use Crosstabs to obtain counts (only) for educ18 by gender by minority. Pivot the table so that you see a two-dimensional table showing only the male employees, with educ18 defining the columns and minority the rows. (Hint: if you don't obtain a pivoting tray at first, use the Pivot menu to obtain one. Paste the resulting table here: Q3. Obtain an interactive scatterplot of Current Salary (salary) on the y-axis, by Previous Experience (prevexp) on the x-axis, and distinguishing different values for minority using the Style box. Paste the figure below and write at least a three- sentence interpretation of the graph.
3. 3. Exercise 2 PART 1: THEORY Q1. Using examples from your own research or field of study, identify a situation in which you might use each of the following tests: a. Independent one-way ANOVA: b. Repeated measures one-way ANOVA: Q2. Mauchly’s test assesses whether: a. Data are normally-distributed b. The variances in different groups are equal c. The assumption of sphericity has been met d. Group means differ Q3. Why is it necessary to follow up significant F-tests with planned or post hoc comparisons? What is the advantage of using these specially designed tests instead of several normal t-tests?
4. 4. PART 2: PRACTICE Launch SPSS and open the data file Telemarketing.sav Assume that in an attempt to maximize profits, a telemarketing company is conducting an experiment to determine which of four scripted sales pitches generates the best revenue. 1500 different telemarketing calls are randomly assigned to one of the four scripts, and the resulting revenue for each call is recorded. Q4. Run the appropriate F-test for this research design, with sales_pitch and revenue as your variables of interest. In the Options menu, request Descriptive statistics and a Homogeneity of variance test. In the Posthoc menu, select Bonferroni. a. Which pitch generated the greatest revenue on average? Paste the Descriptive statistics table from your SPSS output here or attach as a separate sheet. b. Is the homogeneity of variance assumption satisfied for this test? c. Use appropriate academic style to report the findings of the main ANOVA analysis (see PowerPoint slides to refresh your memory). Include the F-test statistic, appropriate df values, and significance level. d. Examine the results of your post hoc analysis. Of all the paired comparisons shown, which was associated with the smallest difference in revenue? Was this comparison significant?
5. 5. PART 1: THEORY Q1. In two sentences, state the purpose of a chi-square test. Q2. List three assumptions that should be met in order to use Pearson’s χ2. 1. 2. 3. Q3. Using an example from your own research or field of study, identify two categorical variables that you suspect might be associated and provide a null and alternative (non-directional) hypothesis. Assume both variables meet the requirements identified in Question 2. Variable 1= Variable 2= H0= H1= Q4. Why do we calculate effect size measures in addition to χ2 values? Name two effect size measures that can be used to supplement chi-square analysis and indicate the circumstances under which you would use each one.