Millisecond Forums

Working with the d-score in SPSS

https://forums.millisecond.com/Topic18265.aspx

By carolin.m - 2/3/2016

Dear all,

I used the template for the SC-IAT which is based on Karpinski, A. & Steinman, R.B. (2006). In the description of the template it is stated that Inquisit calculates d-scores using the improved scoring algorithm as described in Greenwald et al (2003).

Thus do I understand it correctly that I do not need to adjust the d-scores at all in order to work with them in SPSS? So they are ready to be used as I can see them in the output?
And how does it work with the negative values I partly have now? Do I need to recode them?

Thanks a lot in advance!!

Best,
Carolin
By Dave - 2/3/2016

The note in the script's comments means that the Inquisit script a different variant of the D-score than the one Karpinski & Steinman used in their original study. You can use the score Inquisit calculates as-is.

"Inquisit calculates d-scores using the improved scoring algorithm as described in Greenwald et al (2003).
Error trials are handled by requiring respondents to correct their responses according to recommendation (p.214).
This differs slightly from Karpinski & Steinman (2006) who removed noresponse trials from d-score calculations and
replaced error responses with the mean latency + 400ms penalty."

The meaning of positive vs. negative scores is also addressed:

"D-scores obtained with this script:
positive D-scores: positive attitude towards animals
negative D-scores: negative attitude towards animals"

I.e. a *positive* D-score indicates a *positive* attitude towards the target. A *negative* score indicates a negative attitude towards the target. There is no reason to recode negative scores.