InstantForum 2017-1 FinalMillisecond Forumshttps://forums.millisecond.com/Millisecond ForumsWed, 09 Sep 2026 12:52:52 GMT20https://forums.millisecond.com/Topic19646.aspxHello,<br/><br/>I wanted to ensure that I was interpreting my IAT data correctly. <br/><br/>Please correct me if I am wrong, but from my understanding, the D score that we attain from the IAT summary file can indicate how each participant “performed.”<br/>That is, a positive score indicates a higher sorting/association between Target A with attribute A and target B with attribute B. Where as, a negative score would be the opposite. <br/>For example, if my Target A label was Latino and my attribute(s) A were bad, a positive score would indicate faster sorting of Latino and Bad and European and Good (B label and Attribute b).<br/><br/>Given that D scores can range from -2 to 2, would a higher D score indicate a faster sorting/association between Target and Attribute?<br/><br/>Thank you!<br/>JuanMon, 05 Sep 2016 10:34:30 GMTJuanphttps://forums.millisecond.com/Topic19647.aspx&gt; That is, a positive score indicates a higher sorting/association between Target A with attribute A and target B with attribute B. Where as, a <br/>&gt; negative score would be the opposite. <br/><br/>Yes, as detailed (among others) at <a href="https://www.millisecond.com/forums/Topic3444.aspx">https://www.millisecond.com/forums/Topic3444.aspx</a> <br/><br/>&gt; Given that D scores can range from -2 to 2, would a higher D score indicate a faster sorting/association between Target and Attribute?<br/><br/>A higher D-score indicates a *greater difference* in mean response time between the "compatible" and "incompatible" condition. It does not necessarily mean "faster". A D-score is -- in essence -- the difference between <br/><br/>mean response time in *incompatible* trials <br/>and<br/>mean response time in *compatible* trials <br/><br/>expressed in standard deviations.<br/><br/>I.e., (mRTi - mRTc)/sd<br/><br/>Suppose you have the following two hypothetical subjects:<br/><br/>Subject #1:<br/>meanRT(incompatible) = 1800ms<br/>meanRT(compatible) = 1200ms<br/>SD(overall) = 400ms<br/><br/>D(s1) = (1800ms-1200ms)/400ms = 600ms/400ms = 1.5<br/><br/>Subject #2:<br/>meanRT(i) = 3600ms<br/>meanRT(c) = 2400ms<br/>SD(o) = 800ms<br/><br/>D(s2) = (3600ms-2400ms)/800 = 1200ms/800ms = 1.5<br/><br/>You'll notice that both have identical D-scores *despite* substantially different RTs. Hypothetical subject #2 on average takes twice as long to respond compared to hypothetical subject #1. So: Who is faster? Faster with respect to what? That's not the information D is supposed to convey.<br/><br/>Also see <a href="http://www.jakewestfall.org/misc/D_bound.html">http://www.jakewestfall.org/misc/D_bound.html</a><br/>Mon, 05 Sep 2016 10:34:30 GMTDave