Millisecond Forums

As far as I can tell without looking at the actual script, this is correct.

Hmm, not sure I understand the question. I would expect to see a notable difference when looking at a single block, since the block *is* different for the two subject groups. As you correctly noted, group A responded to a flower-good/insect-bad pairng while group B responded to the opposite insect-good/flower-bad combination in said block.

Here's my take on this: In terms of ANOVA, 'pairing order' is just another two-level between-subjects factor. So, to test for any effects of 'pairing order', you  include it in your ANOVA and see if it produces any significant main or interaction effects.

~Dave

P.S.: I can't believe I've wasted my seminal, 500th forum post to an IAT-related question - bummer...:-)

Hi,

With question 1 I only meant that this is how I checked which pairing was done first in which case, but it seems to me now that Inquisit's just deciding the pairing order based on the subject ID. So with even numbered IDs the target's on the right first (after attribute practice), with odd numbered on the left. The reason I'm interested in this is because my data seems to show a huge difference between the two and I'm kinda puzzled over it. I just wanted to make sure I'm looking at the right thing.

Sorry about dragging you into IAT territory again ;).

Best,

Kaarinen

Hi Kaarinen,

  There are relaible order effects for the pairing in the IAT, which are well known and doccumented. However, the good news is that the regression coefficients don't seem to change. In other words, presenting the "consistent" blocks first generally produces a smaller "D" score, but does so in a systematic way, where subject ordering and relative effect size does not change. You should look on Tony Greenwald's website--there's a paper addressing this, but I don't remember exactly what the cite is.

Hi Keith,

Thanks for the reply. I'll try to find the paper you suggested. In my own, slightly unconventional ST-IAT study, I got a significant effect of -0.11 which was a nice finding since it supported the hypothesis  I had. However, upon closer inspection, I realised that the two different pairing conditions* had scores of -.25** and .02 (not significant). I checked the significance of the difference in means with ANOVA and a independent samples t-test, and it is significant at .001 level.

This kinda makes the result difficult to interpret, so I should search for information on this...

Best,

Kaarinen

*Whether the subject got the target paired with attribute A or B first. Here, this means every other participant since Inquisit makes this based on the subject ID (if I understood correctly).

It might be an issue with your "neutral" stimuli. As example, in the "attitude toward coworkers" IAT I did as part of my dissertation, my initial results were aweful (i was using "family members" as the "not coworkers" category, which ended up driving the task). Once I switched it to "other people at the same organization", it got much better). There are other folks out there with some interesting hard-learned lessons on IAT use (I've heard a lot of them). If you want to shoot me an email and describe your task, I might have some insights.

 keith.leavitt@usma.edu