Post on 25-Dec-2015
DEVELOPING A CODING SCHEMEDEVELOPING A CODING SCHEME
ANDAND
SETTING UP YOUR SPSS DATA SETTING UP YOUR SPSS DATA FILEFILE
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DEVELOPING A CODING SCHEME DEVELOPING A CODING SCHEME AND SETTING UP YOUR SPSS AND SETTING UP YOUR SPSS
FILEFILE
The following steps must be taken in the order presented below:
1. Develop a Coding Scheme:
(Ground Rules to be Followed When Coding the Data)
HOW?
– By starting with a blank copy of your survey
(For an example, see the following Faculty Unionization Survey)
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DEVELOPING A CODING SCHEME DEVELOPING A CODING SCHEME AND SETTING UP YOUR SPSS AND SETTING UP YOUR SPSS
FILEFILE
The following steps must be taken in the order presented below:
1. Develop a Coding Scheme
Use a blank survey to:
A. Specify any additional variables that may need
to be added to the data set.
For Example:
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DEVELOPING A CODING SCHEMEDEVELOPING A CODING SCHEME
Campus: ISU NIU SIU ID____ Deadline: Before After
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DEVELOPING A CODING SCHEME DEVELOPING A CODING SCHEME AND SETTING UP YOUR SPSS AND SETTING UP YOUR SPSS
FILEFILE
The following steps must be taken in the orderpresented below:
1. Develop a Coding Scheme--use a blank survey to:
A. Specify any additional variables that may need to be added to the data set.
B. Identify your reverse items (items that will have
to be reverse coded before they are used in any
computations and/or analysis).
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DEVELOPING A CODING SCHEMEDEVELOPING A CODING SCHEME
R R R
R
R
R
Campus: ISU NIU SIUID____ Deadline: Before After
ATTITUDE TOWARD UNIONS:
Liberalism/CONSERVATISM:
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DEVELOPING A CODING SCHEME DEVELOPING A CODING SCHEME AND SETTING UP YOUR SPSS AND SETTING UP YOUR SPSS
FILEFILEThe following steps must be taken in the order presented
below:
1. Develop a Coding Scheme--use a blank survey to:
A. Specify any additional variables that may need to be added to the data set. B. Identify your reverse items (items that will have to be reverse coded before they are used in any computations and/or analysis). C. Assign variable names to all your variables. D. Specify how you wish to code the values of each
variable.E. Specify how you will code missing values (e.g., non- responses).
A true non-response is ordinarily coded as a blank.
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DEVELOPING A CODING SCHEMEDEVELOPING A CODING SCHEME
uni1uni2runi3r
uni4rcon1
con2r
con3
con4
con5r
con6r
con7
con8
Campus: ISU=1 NIU=2 SIU=3ID_____ Deadline: Before=0 After=1
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DEVELOPING A CODING SCHEMEDEVELOPING A CODING SCHEME
age
sex
race
marital
rank rankyr
degree
experyr
instyr
leave
tenure
pay
123
456
0 1125
34
0 1
12
34
0 1
123
45
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34
1 2 3
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2. Create your new SPSS FILE and define the attributes of your variables following the instructions in your handouts entitled:“Instructions for Creating SPSS Files & Using SPSS to Perform Statistical Analysis” and “SPSS Tutorial—Using the Data Editor.”
Make sure to follow the ground rules you have established in your coding scheme. That is, to designate:
A. Variable Names
B. Variable Labels
C. Value Labels (e.g., for variable gender, 0=Male, 1=Female this is especially important for categorical variables.)
D. User-Missing Values
E. Variable Types (i.e., numeric or string)
F. Variable Formats (maximum number of digits and decimals required for coding the values)
(SPSS FILE “UNIONIZATION CODING EXERCISE_THE FILE SHELL”)
DEVELOPING A CODING SCHEME DEVELOPING A CODING SCHEME AND SETTING UP YOUR SPSS AND SETTING UP YOUR SPSS
FILEFILE
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G. Column Formats (column width used to display a variable on the screen)
– NOTE: It may be more convenient to assign the same attributes to several variables by copying and pasting the attributes.
3. Code the data into your SPSS file following the ground
rules established in your coding scheme and observed
when creating your SPSS file.
4. Reverse code your reverse items--only after all the coding is
completed (Menu Bar: Transform, Recode into a new var.)
See handout entitled “SPSS Tutorial: Modifying Data Values.”(SPSS FILE “UNIONIZATION CODING EXERCISE_FICTITIOUS DATA”)
DEVELOPING A CODING SCHEME AND DEVELOPING A CODING SCHEME AND SETTING UP YOUR SPSS FILESETTING UP YOUR SPSS FILE
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5. Compute and print summary/descriptive statistics--e.g., mean, std. dev., min., and max. for metric variables; and frequencies, min., and max. for categorical variables
(Menu Bar: Analyze, Descriptive Statistics)
6. Examine the data and summary statistics (e.g., frequencies, min. & max. values) to spot and correct coding errors.
7. Calculate reliability ONLY for each of your summated multi-item scale and, (a) identify items detracting from reliability, and (b) refine the scale accordingly
(Menu Bar: Analyze, Scale, Reliability Analysis, Statistics--“Inter-item correlations” and “Scale if item deleted”) (SPSS FILE “UNIONIZATION CODING EXERCISE_FICTITIOUS DATA”)
DEVELOPING A CODING SCHEME DEVELOPING A CODING SCHEME AND SETTING UP YOUR SPSS AND SETTING UP YOUR SPSS
FILEFILE
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8. Create a composite/summated variable for each summated multi-item scale
(Menu Bar: Transform, Compute--Target Variable = a mathematical expression)See handout entitled “SPSS Tutorial: Calculating New Data Values.”
(SPSS FILE “UNIONIZATION CODING EXERCISE_FICTITIOUS DATA”)
9. Compute Descriptive Statistics for different subgroups separately
(Menu Bar: Data, Split File, Organize Output by Groups--specify the grouping variable) OR (Menu Bar: Analyze, Compare Means, Means, Dep. List, Indep. List, Select Options, OK)
10. Save and print your SPSS data file (Menu Bar: File, Save As…)11. Analyze the data (Menu Bar: Analyze--select analysis options)
DEVELOPING A CODING SCHEME DEVELOPING A CODING SCHEME AND SETTING UP YOUR SPSS AND SETTING UP YOUR SPSS
FILEFILE