Scoring the IAT (case 12779)

[ucsbbritt]

This syntax was for a standard (racial bias) IAT. In fact, I believe that I used the exact same formatting, albeit different photos, as the version featured as an example in the DirectRT package. Hope that helps,

Paul

I am new to Direct RT, and i am looking to score the sample race-IAT in Direct RT, so would this syntax apply to that?
thank you

[padennis]

I am new to Direct RT, and i am looking to score the sample race-IAT in Direct RT, so would this syntax apply to that?
thank you

Hi,
It's been so long since I've looked at the demo that I'm not sure whether my version directly corresponds to it. (I'd check, but I no longer have DirectRT on my computer.) I've attached the kind of run file that should produce a data file that can be analyzed via the SPSS syntax file that I posted earlier. The essential elements are that blocks 3 and 5 represent the blocks of trials that are compared. For example, block 3 pairs race A with adjective 1 and race B with adjective 2. Block 5 pairs race A with adjective 2 and race B with adjective 1. Again, I'm pretty sure that this run file is either a copy of or closely corresponds to the demo file.

Just follow the instructions in the SPSS syntax file (and be sure to read the article that I mentioned earlier to understand the calculations, which are really quite basic). Good luck!

[ucsbbritt]

okay great! thanks for the help.

[kosta]

I used the syntax posted on this website to convert my IAT data into d scores (thank yo iso much for sharing). I analyzed the data several months ago and found an effect in the opposite direction from predicted. Then, today when i opened the file again and analyzed the data--the effect was gone! I re-ran the syntax front the original (raw) data and generated a new set of d-scores. those d-scores are identical to the ones that are giving me no effect except for the fact hat they have different sings (i.e., + and -). The change in the sign is not systematic and seems to vary randomly (i.e., sometimes the signs are the same and sometimes they are different from the ones giving me no effect). Even more surprisingly, the effect is now of the same magnitude as a few months ago but in the predicted direction (i.e., opposite from what I observed at first). I have re-ran the IAT syntax omn the original data several times today and I always get the same output of d-scores (but this output seems to be different from the one i got before)

Does anybody have any insight into this very peculiar and rather scary story of SPSS? Has anybody experienced the change of signs I am describing? As it stands, i cannot at all trust what I am getting form this particular study.

Please help to save my data if you can.

[mdeegan]

According to post # 3...using the syntax provided by Greenwald...

"In DirectRT, your trial #rs must begin with #1 (and go to whatever). SO: if the range in DirectRT is 5-380, you need to transform it to range from 1-376."

I believe this is because we want to drop the first two trials of each block for the original scoring method of the IAT.
When we look at the syntax file attached...the following line is used to compute the "Original IAT measure":


*Drop 1st 2 trials (this was part of the conventional procedure).
SELECT IF (TRIAL GT 2).

However, I believe there are two problems with this procedure, though I am not sure...if anyone can speak to these two potential issues, I would appreciate it:

1. This drops trials 1 and 2 from the first block (which is a single-pairing practice that isn't analyzed anyway) , but the IAT scoring procedure should drop the first two trials from EACH BLOCK.

2. The trial numbers in DirectRT do not reflect the order that these trials were presented to the subject-just the order they are programmed as-which would make this the wrong variable to reference anyway.


Also, is there any reason to actually save blocks 1,2, and 5? I don't, and besides the aforementioned problems with calculating the traditional scoring measure, this syntax appears to work just fine.

[jwoolley]

According to post # 3...using the syntax provided by Greenwald...

"In DirectRT, your trial #rs must begin with #1 (and go to whatever). SO: if the range in DirectRT is 5-380, you need to transform it to range from 1-376."

I believe this is because we want to drop the first two trials of each block for the original scoring method of the IAT.
When we look at the syntax file attached...the following line is used to compute the "Original IAT measure":


*Drop 1st 2 trials (this was part of the conventional procedure).
SELECT IF (TRIAL GT 2).

However, I believe there are two problems with this procedure, though I am not sure...if anyone can speak to these two potential issues, I would appreciate it:

1. This drops trials 1 and 2 from the first block (which is a single-pairing practice that isn't analyzed anyway) , but the IAT scoring procedure should drop the first two trials from EACH BLOCK.

2. The trial numbers in DirectRT do not reflect the order that these trials were presented to the subject-just the order they are programmed as-which would make this the wrong variable to reference anyway.


Also, is there any reason to actually save blocks 1,2, and 5? I don't, and besides the aforementioned problems with calculating the traditional scoring measure, this syntax appears to work just fine.

This is my first time trying to use DirectRT and I'm running into some similar issues trying to adapt this syntax so it works with the way I programmed my csv file to run in Direct RT. I've had to make several additional adjustments based on what I saved and what I didn't. I think it all could have been easier if I hadn't saved the trial blocks (as you suggested), because I've had to do some maneuvers so that the eventual data file I'm using has trials that start at 1, and I'm not even sure that matters. Anyway...

I think you're right about dropping the first two trials in each test block. Do do this, you have to add additional commands, (which will be different depending on how many trials you have) e.g. :

SELECT IF (TRIAL GE 3 AND TRIAL LE 32) OR (TRIAL GE 35).

As far as the presentation of the stimuli, "trial" does in fact tell you the order in which they were each presented. It is the "order" variable that tells you the order they were programmed. I changed "order" to "number" so I could calculate the new "order" variable. That was also kind of a pain because DirectRT didn't save any record of which of the pairings it randomly used (although maybe it could have and I just didn't click the right box), so I had to use syntax similar to the syntax above .

[baysa]

Hello,

Is anyone willing to share SPSS syntax for scoring the 4-block Single Category IAT? I've seen syntax on here for what appears to be a 5-block single category (or maybe single target, which is conceptually similar but slightly different in structure) IAT. Alternatively, is anyone able to help me alter the attached syntax I have to conform to the scoring guidelines outlined in Karpinski and Steinman (2006; also attached)? I would appreciate any guidance that can be given. Thanks in advance!SC-IAT Scoring Syntax.sps