DEVELOPING A CODING SCHEME AND SETTING UP YOUR SPSS DATA FILE

1. DEVELOPING A CODING SCHEMEANDSETTING UP YOUR SPSS DATA FILE

2. DEVELOPING A CODING SCHEME AND SETTING UP YOUR SPSS FILE The following steps must be taken in the order presented below: • 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)

3. DEVELOPING A CODING SCHEME (Continued on the next slide)

4. DEVELOPING A CODING SCHEME

5. DEVELOPING A CODING SCHEME AND SETTING UP YOUR SPSS FILE The following steps must be taken in the order presented below: • Develop a Coding Scheme Use a blank survey to: • Specify any additional variables that may need to be added to the data set. For Example:

6. DEVELOPING A CODING SCHEME ID____ Campus: ISU NIU SIU Deadline: Before After

7. DEVELOPING A CODING SCHEME AND SETTING UP YOUR SPSS FILE The following steps must be taken in the orderpresented below: 1. Develop a Coding Scheme--use a blank survey to: • 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).

8. DEVELOPING A CODING SCHEME ID____ Campus: ISU NIU SIU Deadline: Before After ATTITUDE TOWARD UNIONS: R R R Liberalism/CONSERVATISM: R R R

9. DEVELOPING A CODING SCHEME AND SETTING UP YOUR SPSS FILE The following steps must be taken in the order presented below: 1. Develop a Coding Scheme--use a blank survey to: • 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. • Specify how you will code missing values (e.g., non- responses). • A true non-response is ordinarily coded as a blank.

10. DEVELOPING A CODING SCHEME ID_____ Campus: ISU=1 NIU=2 SIU=3 Deadline: Before=0 After=1 uni1 uni2r uni3r uni4r con1 con2r con3 con4 con5r con6r con7 con8

11. DEVELOPING A CODING SCHEME 123 456 age sex 0 1 125 34 race marital 0 1 rank 34 12 rankyr degree 1 0 experyr 123 45 instyr 123 45 leave 12 34 tenure 2 3 1 pay

12. DEVELOPING A CODING SCHEME AND SETTING UP YOUR SPSS FILE 2.Create your new SPSS FILE and define the attributes of your variablesfollowing 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: • Variable Names • VariableLabels • Value Labels (e.g., for variable gender, 0=Male, 1=Female this is especially important for categorical variables.) • User-Missing Values • Variable Types (i.e., numeric or string) • Variable Formats (maximum number of digits and decimals required for coding the values) (SPSS FILE “UNIONIZATION CODING EXERCISE_THE FILE SHELL”)

13. DEVELOPING A CODING SCHEME AND SETTING UP YOUR SPSS FILE • Column Formats (column width used to display a variable onthe screen) • NOTE: It may be more convenient to assign the same attributes to several variables by copying and pasting the attributes. • Code the data into your SPSS file following the ground rules established in your coding scheme and observed when creating your SPSS file. • 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”)

14. DEVELOPING A CODING SCHEME AND SETTING UP YOUR SPSS FILE • 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) • Examine the data and summary statistics (e.g., frequencies, min. & max. values) to spot and correct coding errors. • Calculate reliabilityONLY 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”)

15. DEVELOPING A CODING SCHEME AND SETTING UP YOUR SPSS FILE • Create a composite/summated variablefor 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”) • 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) • Save and print your SPSS data file (Menu Bar: File, Save As…) • Analyzethe data(Menu Bar: Analyze--select analysis options)

16. QUESTIONS ORCOMMENTS?