By maf1974 - 10/2/2014
Hi All,
As a new user of Inquisit Web 4, I have read through the post from Dave about how to interpret IAT data (https://www.millisecond.com/forums/Topic3444.aspx)
The post says: The final 'd' score for a given participant thus appears on the last row of data for that participant. Inquisit reports 3 d scores, which appear in the last 3 columns labeled "expressions.da", "expressions.db", and "expression.d".
I can see the three columns corresponding to the 'da', 'db', and 'd' scores but in the AgeIAT file I'm looking at there is no "final d score" provided in the bottom row. The bottom row is just another row measuring one specific stimulus item from the IAT. The AgeIAT is from the list of scripts that Dave suggests does compute d (i.e., it is not an outdated script as was suggested to another user experiencing the same issue as me).
Is anyone able to offer me some thoughts on this? Do I have to take an average of the entire d column to know each participants d score? That will be very time-consuming as I have approx 200 participants. Apologies for the noob question.
Thanks,
Mike
|
By Dave - 10/2/2014
A D-score is a summary statistic (as difference of means scaled by SD, to be more precise). The script computes it as the data comes in trial-by-trial: Every *row* can thus be read / understood as "this is the D-score *given all the data available up to this point*". Consequently, the final row represents the final D-score -- that's when all the data are in, after all.
|
By maf1974 - 10/2/2014
Thanks Dave, that makes a lot more sense. So basically a cumulative score of 'total d' is being provided with each new row of information. Thanks for explaining that.
Mike
:o)
|
By Dave - 10/2/2014
Exactly. It's D calculated based on all the data up to and including the given trial (=row of data) you're looking at.
|
|