Use the following SPSS data set entitled:
calsep for program evaluation class week 9.sav
With the above data set, run basic descriptive statistics (frequencies, mean, median, mode, standard deviation) on the following variables: TIJ30DA, TIJ30DB, TIJ30DC, TIJ30DD, TIJ30DE.
These variables come from responses to the following contingent questions:
Have you injected [a speedball (heroin & cocaine mixed), heroin, ...] in the last 30 days? Yes1No0Skip to 62Refuse to Answer8How many times did you inject [a speedball (heroin & cocaine mixed), heroin, ...] in the last 30 days? |__|__|__|__|Don't Know7777Refuse to Answer8888In the last 30 days, have you used [a speedball (heroin & cocaine mixed), heroin, ...] without injecting? Yes1No0Refuse to Answer8
Speedball
Heroin
Powder Cocaine
Crack Cocaine
Amphetamines
Q60
|__|
|__|
|__|
|__|
|__|
Q61
|__|__|__|__|Tij30da
|__|__|__|__|Tij30db
|__|__|__|__|Tij30dc
|__|__|__|__|Tij30dd
|__|__|__|__|Tij30de
Q62
|__|
|__|
|__|
|__|
|__|
Select the following tabs: Analyze, Descriptive statistics, Frequencies. Check the display frequency box, find and select the above variables in the menu box on the left and then push the Statistics button. In this new window, select boxes for mean, median, mode, and standard deviation. Once selected, push the “Continue” button on the Statistics menu, and then “Okay” on the frequency menu to see data output.
Reviewing the summary statistics and frequency tables, you will note results that don’t make sense. For instance, we know from prior studies that most injection-drug users inject about 60 times a month, yet mean injections are all very high in this sample for all of these variables.
To fix this you will need to recode the 7777, 8888, and 9999. There are a variety of ways to do this, but one simple way is to recode the responses into a new variable. We will create a new variable because you never want to change your raw results even when they are in error.
To recode into a new variable, conduct the following steps. I will use tij30da as an example.
Select the Transform tab followed by Recode into different variable. This opens the recode into different variable window. Select tij30da and move it into the open window. Under “output variable” come up with a new 8 character name that does not start with a number. In the label box, I like to include the variable name {8 character} and then a description. It can be as long or as short as you like, but should note that this is a transformed variable of speedball injection frequency in the last 30 days and that it removes the 7777, 8888, and 9999. Next select the Old and new values button. This opens a new window. Under old value, in the value box enter 9999 (there are no 7777 or 8888 in tij30da). In the new value box you would select to transform these responses into “system missing.” Once you select “system missing” the Add button will be activated. Push it to make this change.
InstructionsConduct this transformation for the other injection frequency variables. Turn in your data output files that show your work.