Hello,

I encountered a problem while running my IAT analysis. I used the generic IAT SPSS syntax provided by Dr. Anthony Greenwald in his website.
I need the D_biep for each subject. However when I am running the analysis at some point (I think in aggregate command) some data gets lost. I ran the syntax step by step and this is when some information disappears.


Therefore in the following steps, as I continue running the syntax, D_biep is not calculated as those cells are empty.

Does anyone know how to solve this problem?

Thanks in advance!

You should *only* use Dr. Greenwald's SPSS syntax if you also used the IAT script provided by Dr. Greenwald. If you used any other script, the syntax will not work. Note that the IAT scripts available in the millisecond.com library all automatically calculate and log D-scores (d_biep), i.e. there usually is no need for running any SPSS syntax if you used one of those scripts.

Thank you so much for your immediate response!

I used the script in the website and I was successful by running the syntax provided in millisecond.
However, I wanted to make sure that I am using the latest recommended calculations for D_biep scores.
Is D_biep score calculated according to the latest recommended analysis or is it the previous version?

Also, I want to exclude participants with latencies below 400 ms for example, I know that these are excluded in teh syntax provided by Dr. Greenwald's generic IAT SPSS syntax. I would really appreciate if you could also explain how the D_biep scores are calculated in the millisecond syntax.

> Is D_biep score calculated according to the latest recommended analysis or is it the previous version?

Not sure which two versions you are referring to here. Could you please specify those? D_biep is "D with built-in error penalty" (=biep), which is what Greenwald et al. (2003; https://faculty.washington.edu/agg/pdf/GB&N.JPSP.2003.pdf ) recommend and which is what the Inquisit scripts calculate.

> I want to exclude participants with latencies below 400 ms for example, I know that these are excluded in teh syntax provided by Dr. Greenwald's generic IAT SPSS syntax

The "IAT SPSS Script" at https://www.millisecond.com/download/library/iat/ does that too.

* Mark trials with latency < 400 ms (to provide a count of these) .
COMPUTE FLAG_400 = 0 .
IF (LATENCY < 400) FLAG_400 = 1 .
...
* Record criteria for potential use in subject discards .
* This count can later be used as the basis for subject discard .
AGGREGATE OUTFILE = 'CRITERIA.SAV'
 / BREAK = SUBJECT ORDER
 / PCT_300 = PGT(FLAG_300,0)
 / PCT_400 = PGT(FLAG_400,0)
 / PCT_10K = PGT(FLAG_10K,0)
 / AVELTNCY ERRORPCT = MEAN (LATENCY ERROR)
 / NTRIALS = N .

The Inquisit scripts *themselves* don't discard any data (and can't), because the recommendation is to throw away the participant's entire data set if s/he exhibits an excessive amount of responses below 400ms.

> I would really appreciate if you could also explain how the D_biep scores are calculated in the millisecond syntax.

I don't understand this question. What exactly do you need me to explain -- specific snippets of the syntax or whether the D-scores are calculated according to Greenwald et al. (2003; they are)?

       

In the zip file here (https://faculty.washington.edu/agg/iat_materials.htm) there are three different SPSS syntax. I wanted to try running all of them because I assumed they were revised versions of D_biep calculation provided in the millisecond page. The syntax in the zip file includes the  following note:
"** REVISION NOTES ** .
*1. First version, 26 Nov 2005.
*2. Revised 26 Aug 07 (but this revision contained errors in some variable names).
*3. Revised 29 Dec 07 to fix the errors in Revision 2."

Therefore I thought the latest version was not 2003 but a revised 2007 version.

I also found this information about the three different computation provided in the zip file

*"D_biep.Inquisit Generic IAT SPSS syntax form.26Aug07.doc"
* Computes the D1 measure (using "built in" error penalty produced by the procedure
* of requiring correct response on each trial and recording latency to occurrence of
* that response (even after prior occurrence of an error response).

*"D_2SDep.Inquisit Generic IAT SPSS syntax form.26Aug07.doc"
* Computes the D3 measure (replacing error latencies with mean of correct
* latencies from the block in which the error occurred plus twice the SD of
* correct latencies).

*"D_600ep.Inquisit Generic IAT SPSS syntax form.26Aug07.doc"
* Computes the D4 measure (replacing error latencies with mean of correct latencies
* from the block in which the error occurred plus 600 milliseconds)."

I am wondering if the compuation provided in the millisecond webpage is parallel to these versions.