Dear,
I have designed a variation to the IAT to measure brand personality. I have two attributes ('Ja' and 'Nee' - 'Yes' and 'No) and 24 pictures (items) which are presented and to which the participant has to indicate to which attribute it belongs. There are no correct or incorrect answers. Although this is by far not true implicit manner, I do want use it to try and tap the unconscious, arguing that the participant will go on 'auto pilot' mode after sevaral words, seeing that it is very important that he/she reacts as quick as possible.
Anyway, I am trying to make sure that the average reaction time per stimulusitem is recorded. Do I then have to make 24 trials? For now I have simply added 'stimulusonset' and 'latency' to the data columns. If I am correct this ads the response time per item to the data, and then I can calculate the mean time in SPSS. Is this correct and enough? And if so which one of the two '('stimulusonset' or 'latency' is better? The seem the same?). Is there an easier way to straigh away calculate the mean reaction time per item? So that I can also use it in my summery?
I have attached a part of the script I am using. I have used a previously made SC-IAT, so part of the script is 'useless', like the expressions.da, for this purpose.
Thank you very very much for your help.
Kind regards,
Celeste Miller
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<item attributeAlabel>
/1 = "Ja"
</item>
<item attributeBlabel>
/1 = "Nee"
</item>
<item attributeA>
/1 = "23plusone2012_voorkant.jpg"
/2 = "23plusone2012_voorkant2.jpg"
/3 = "23plusone2012_voorkant3.jpg"
/4 = "23plusone2012_voorkant4.jpg"
/5 = "23plusone2012_voorkant5.jpg"
/6 = "23plusone2012_voorkant6.jpg"
/7 = "23plusone2012_voorkant7.jpg"
/8 = "23plusone2012_voorkant8.jpg"
/9 = "23plusone2012_voorkant9.jpg"
/10 = "23plusone2012_voorkant10.jpg"
/11 = "23plusone2012_voorkant11.jpg"
/12 = "23plusone2012_voorkant12.jpg"
/13 = "23plusone2012_voorkant13.jpg"
/14 = "23plusone2012_voorkant14.jpg"
/15 = "23plusone2012_voorkant15.jpg"
/16 = "23plusone2012_voorkant16.jpg"
/17 = "23plusone2012_voorkant17.jpg"
/18 = "23plusone2012_voorkant18.jpg"
/19 = "23plusone2012_voorkant19.jpg"
/20 = "23plusone2012_voorkant20.jpg"
/21 = "23plusone2012_voorkant21.jpg"
/22 = "23plusone2012_voorkant22.jpg"
/23 = "23plusone2012_voorkant23.jpg"
/24 = "23plusone2012_voorkant24.jpg"
</item>
<picture attributeA>
/ items = attributeA
/ size = (30%, 30%)
</picture>
*************************************************
<block compatibletest>
/ bgstim = (attributeAleft, attributeBright, reminder, merk)
/ trials = [1-96 = noreplace(attributeA)]
/ responsemode = correct
/ ontrialend = [if(block.compatibletest.latency <= 10000) values.sum1b = values.sum1b + block.compatibletest.latency]
/ ontrialend = [if(block.compatibletest.latency <= 10000) values.n1b = values.n1b + 1]
/ ontrialend = [if(block.compatibletest.latency <= 10000) values.ss1b = values.ss1b + (block.compatibletest.latency * block.compatibletest.latency)]
</block>
*********************************
<data>
/ columns = [date, time, subject, blockcode, blocknum, trialcode, trialnum, response, correct, latency, stimulusonset, meanlatency, stimulusnumber, stimulusitem, expressions.da, expressions.db, expressions.d ]
</data>