Quote Originally Posted by mdeegan View Post
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 .