Question 1: Descriptive Statistics
The first step in the analysis of any data file is to obtain descriptive statistics on each of your variables. These can be used to check for out-of-range cases, to explore the distribution of the scores, and to describe your sample in the Method section of a report.
Use the instructions in Chapter 6 and Chapter 7 of the SPSS Survival Manual to answer the following questions concerning the variables included in the survey.sav data file.
(a) What is the mean age of the sample? What is the age range of the sample (minimum and maximum values)?
(b) What is the percentage of males and females in the sample? Did any of the sample fail to indicate their gender?
(c) What percentage of the sample were smokers?
(d) Inspect the distribution of scores on the Total Negative Affect scale. How normal is the distribution? Are there any cases that you would consider outliers?
Question 2: Checking the Reliability of a Scale
If you use scales or standardized measures in your research (this is common in psychological research) it is important to assess the reliability (internal consistency) of the scores on the scale in your sample. The following exercise gives you some practice in this process.
Follow the procedure in Chapter 9 of the SPSS Survival Manual to assess the reliability of the following scales. You will need to refer to the codebook in the appendix to identify the items that make up each of the scales (survey5ED.sav page 333).
(a) Optimism scale (op1 to op6)
(b) Perceived Control of Internal Stress scale (pc1 to pc18)
(c) Self-esteem scale (sest1 to sest10)
You will need to manipulate certain items prior to calculating the scale reliability. These items will require reversing of negatively worded items. Please refer to page 87-88 of Pallant 6th ed. The reason why these items need to be reversed is because some of the responses are worded positively while other items are negatively worded (inverse).
Example:
Optimism Scale (located in page 333)
Strongly disagree 1 2 3 4 5 Strongly agree
1.____In certain times I usually expect the best.
2.____If something can go wrong for me it will. (negatively worded-a high score in this item signifies low optimism)
3.____I’m always optimistic about my future.
4.____I hardly ever expect things to go my way. (negatively worded-a high score in this item signifies low optimism)
5.____Overall I expect more good things to happen to me than bad,
6.____I rarely count on good things happening to me. (negatively worded high score in this item signifies low optimism)
Read through steps 1-7. Once you recode items 2, 4, and 6, you will then be able to move on to calculating reliability (page 102-103). You will find on page 331 the items that require reversing under the Coding Instructions column.
Question 3: Correlation
Using the data file staffsurvey.sav follow the instructions in Chapter 11 to explore the relationship between the total satisfaction and age. Present the results in a brief report.
Use the instructions in Chapter 11 to generate a full correlation matrix to check the intercorrelations among the following variables.
age
city
service
employment status