Millisecond Forums

SPSS Syntax

https://forums.millisecond.com/Topic8333.aspx

By Sabi - 7/2/2012

Hi There


I made a research with the IAT and I used the ready SPSS Syntax from Inquisit to calculate the D-Score - which worked fine...


At the end of the Syntax file there is an option to reverse the scoring of the IAT - what is this needed for? i couldnt find any information about it? do i have to do this or can i stop with the first step of the Syntax?



Thanks for any help!!


Beste regards


Sabi




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


** TO REVERSE THE SCORING OF THE IAT, REMOVE THE ASTERISKS **


** FROM THE NEXT FOUR COMMAND LINES.                       **


************************************************************* .



* COMPUTE D_biep = 0 - D_biep .


* COMPUTE D_biep_a = 0 - D_biep_a .


* COMPUTE D_biep_b = 0 - D_biep_b .


* VARIABLE LABELS


    D_biep   'd score all blocks' 


  / D_biep_a 'd score 1st blocks'


  / D_biep_b 'd score 2nd blocks' .



FORMAT D_biep D_BIEP_a D_BIEP_b D_BIEP (F6.3) SUBJECT (F7.0) 


    Na Nb (F4.0) M1a M2a M1b M2b (F7.1)


    ERR1a ERR2a ERR1b ERR2b ERR_1 ERR_2 (F5.1) .



SAVE OUTFILE = 'D_BIEP_temp.SAV' .


DESCRIPTIVES  ALL .



**************************************************************.


**** STEP 3: COMBINE MEASURES AND SAVE ****.


**************************************************************.



*Add labels to CRITERIA.SAV .


GET FILE = 'CRITERIA.SAV' .


VARIABLE LABELS


   PCT_300 '% latencies below 300 ms'


 / PCT_400 '% latencies below 400 ms'


 / PCT_10K '% latencies above 10,000 ms'


 / AVELTNCY 'Overall average latency (ms)'


 / ERRORPCT 'Overall % errors' 


 / NTRIALS 'Total # of combined-task trials' .



FORMAT AVELTNCY (F7.1) PCT_300 PCT_400 PCT_10K ERRORPCT (F6.1) SUBJECT (F7.0) .



SAVE OUTFILE = 'CRITERIA.SAV' .



*Combine and save .


MATCH FILES FILE = 'D_BIEP_temp.SAV' / FILE = 'CRITERIA.SAV' /BY SUBJECT  .



SAVE OUTFILE = 'D_BIEP.SAV' .



* Note: No subjects have yet been discarded.  However, each record contains .


* three variables that might be used for discard .


* PCT_300 = overall % of responses with latencies below 300 ms .


* ERRORPCT = overall error % .


* AVELTNCY = overall average latency .


* [Note that 'aveltncy' was computed _BEFORE_ discard of latencies above 10000 ms] .



GET FILE = 'D_BIEP.SAV' .


DESCRIPTIVES ALL .



By Dave - 7/2/2012

At the end of the Syntax file there is an option to reverse the scoring of the IAT - what is this needed for?


It's needed if you flipped "good" and "bad" attributes in the script. Usually attribute A is "good", attribute B is "bad". If you switched that (i.e., attribute A = bad; attribute B = good), D's sign will be wrong and needs to be reversed.

By Sabi - 7/4/2012

Thanks so much for your help! you are great!