KNR 445

Statistical Applications in Science & Technology

Assignment
Becoming Familiar with SPSS for Windows

The purpose of this assignment is to acquaint you with some of the powerful data handling features available in SPSS for Windows. You will use the smoking dataset from the CDC (Center for Disease Control).

General Questions

1. Indicate which scale of measurement each of the following belongs to:
a. reaction time
b. urbanicity (1 = urban; 2 = suburban; 3 = rural)
c. the numbers on soccer players' jerseys
d. type of psychotherapy
e. class size
f. religious affiliation (1 = protestant; 2 = Catholic; 3 = Jewish; etc...)
g. restaurant rating (one star to 5 stars)
h. astrological sign
i. miles per gallon

2. For all those in question 1, which are qualitative variables?

3. For each of the following, illustrate your reasoning with a variable from the list in q.1:
a. Can a ratio variable be reduced to an ordinal variable?
b. Can an ordinal variable be promoted to a ratio variable?
c. Can an ordinal variable be reduced to a nominal variable?

4. Round off the following numbers as specified:
a. to the nearest whole number: 8.545; -43.2; 123.01; 0.095
b. to the nearest tenth: 27.33; 1.9288; -0.38; 4.9746
c. to the nearest hundredth: -31.519; 76.0048; 0.82951; 40.7442

SPSS for Windows

The Data Menu

One of the most powerful features of SPSS is the ability to manipulate data files. The Data menu lists the various manipulations possible.

Define Variable: works similar to clicking on the top row of a column.

Insert Variable: allows you to add a column within existing column; go to the Variable View window to annotate the variable.

Sort Cases: sort the cases in the data set based on any existing variable.

Split File: allows you to run procedures on any definable subset of the data set. Always remember to reset to Analyze all cases or only the last defined subsets will be included.

Select Cases: allows you to create subsets based on specific values of variables in the data set. Only the cases selected will be included in the procedures.

Homework: Put your name, the date, and the assignment number in the top right corner of the first page of your submitted homework.

1. Create a data file of the CDC data using the SPSS Data Editor. Save it to hard disk and to your floppy disk.

2. Create a new NUMERIC variable called Region, specifying the geographical location of the state. There should be 6 regions: 1=North East, 2=South East, 3=North Central, 4=South Central, 5=North West and 6=South West. Under the variable region, assign each state to the appropriate geographical region (this is not a geography test but at least be close). Save the data set on completion of this task (Note: do not save over your original file).

3. Use the dataset updated in 2) for these questions:

a. Sort the data file by region with the states arranged within each region in alphabetical order.

b. Arrange the states within each region in ascending order of tax per pack of smokes.

c. From the menu "Analyze", select "descriptive statistics", then choose "descriptives". Analyze the variable "tax", and note the output.

4. Use a menu command to split the file by region. From the menu "Analyze", select "descriptive statistics", then choose "descriptives". Analyze the variable "tax". How does the output compare to that produced in question 3? Now, turn the split file off.

5. Using a menu command (look for this on your own), create a new variable Region2 by reclassifying states from the 6 regions identified above into 3 larger regions, the West, the Central, and the East. Each of the three regions should then be rearranged so that the states are in descending order based on smoker deaths.

Independent and Dependent Variables

On your own: Play with the Insert feature under SPSS Viewer, to annotate your output.

When you are satisfied that you can navigate within SPSS easily, that you know how to use the Help feature of SPSS, and that you can create and edit an SPSS data file, you are finished assignment 1.

Notes:

Data files are stored by SPSS with the suffix .sav
Output files are stored by SPSS with the suffix .spo

Remember to use descriptive names for your files.