Monday, 9 February 2015

State-Trait Anxiety Inventory (STAI): SPSS Script

The State-Trait Anxiety Inventory (STAI) is a psychological inventory based on a 4-point Likert scale and consists of 40 questions on a self-report basis. 

Below is a short script for SPSS which will help speed up the coding process. A version that runs in R is also in the pipeline. 

All items should be labeled as separate numeric variables as stai1 and taiy1 ...etc

The script computes and prints the results for all reverse scored items and then calculates and prints state and trait scores. It will also produce Cronbach's Alpha coefficients.

The original scoring key for the STAI can be found here.



*Part 1 - reverse scoring of specific items

COMPUTE stai1r = 5 - stai1.
EXECUTE.

COMPUTE stai2r = 5 - stai2.
EXECUTE.

COMPUTE stai5r = 5 - stai5.
EXECUTE.

COMPUTE stai8r = 5 - stai8.
EXECUTE.

COMPUTE stai10r = 5 - stai10.
EXECUTE.

COMPUTE stai11r = 5 - stai11.
EXECUTE.

COMPUTE stai15r = 5 - stai15.
EXECUTE.

COMPUTE stai16r = 5 - stai16.
EXECUTE.

COMPUTE stai19r = 5 - stai19.
EXECUTE.

COMPUTE stai20r = 5 - stai20.
EXECUTE.

COMPUTE taiy1r = 5 - taiy1.
EXECUTE.

COMPUTE taiy3r = 5 - taiy3.
EXECUTE.

COMPUTE taiy6r = 5 - taiy6.
EXECUTE.

COMPUTE taiy7r = 5 - taiy7.
EXECUTE.

COMPUTE taiy10r = 5 - taiy10.
EXECUTE.

COMPUTE taiy13r = 5 - taiy13.
EXECUTE.

COMPUTE taiy14r = 5 - taiy14.
EXECUTE.

COMPUTE taiy16r = 5 - taiy16.
EXECUTE.

COMPUTE taiy19r = 5 - taiy19.
EXECUTE.

*******************************************

*Part 2 - calculating state and trait anxiety scores

COMPUTE STAnxiety = (stai1r+stai2r+stai3+stai4+stai5r+stai6+stai7+stai8r+stai9+stai10r+stai11r+stai12+stai13+stai14+stai15r+stai16r+stai17+stai18+stai19r+stai20r)/20.
EXECUTE.

COMPUTE TAAnxiety = (taiy1r+taiy2+taiy3r+taiy4+taiy5+taiy6r+taiy7r+taiy8 +taiy9+taiy10r+taiy11+taiy12+taiy13r+taiy14r+taiy15+taiy16r+taiy17+taiy18+taiy19r+taiy20)/20.
EXECUTE.


*********************************************************************************

*Part 3 calculating reliability scores 

* State Anxiety

RELIABILITY
 /VARIABLES=stai1r stai2r stai3 stai4 stai5r stai6 stai7 stai8r stai9 stai10r stai11r stai12 stai13 stai14 stai15r stai16r stai17 stai18 stai19r stai20r
 /SCALE('ALL VARIABLES') ALL
 /MODEL=ALPHA.

*Trait Anxiety

RELIABILITY
 /VARIABLES=taiy1r taiy2 taiy3r taiy4 taiy5 taiy6r taiy7r taiy8 taiy9 taiy10r taiy11 taiy12 taiy13r taiy14r taiy15 taiy16r taiy17 taiy18 taiy19r taiy20
 /SCALE('ALL VARIABLES') ALL

 /MODEL=ALPHA.