User Manual: Inquisit Skin Tone IAT


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									Skin Tone Implicit Association Test (IAT) - with pictures
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Main Inquisit programming: Sean Draine (seandr@millisecond.com)
last updated:  02-23-2022 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Script Copyright © 02-23-2022 Millisecond Software

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BACKGROUND INFO 	
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The Implicit Association Task (Greenwald, McGhee, & Schwartz, 1998) is a widely-used cognitive-behavioral paradigm
that measures the strength of automatic (implicit) associations between concepts in people’s minds relying 
on latency measures in a simple sorting task.
 
The strength of an association between concepts is measured by the standardized mean difference score of 
the 'hypothesis-inconsistent' pairings and 'hypothesis-consistent' pairings (d-score) (Greenwald, Nosek, & Banaji, 2003). 
In general, the higher the d-score the stronger is the association between the 'hypothesis-consistent' pairings 
(decided by researchers). Negative d-scores suggest a stronger association between the 'hypothesis-inconsistent' pairings.

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).

D-scores obtained with this script:
Positive d-scores: support a stronger association between 'Light Skinned People-Good' and 'Dark Skinned People-Bad' than for the opposite pairings
Negative d-scores: support a stronger association between 'Dark Skinned People-Good' and 'Light Skinned People-Bad' than for the opposite pairings

References:
Greenwald, A. G., McGhee, D. E., & Schwartz, J. K. L. (1998). Measuring individual differences in implicit cognition: 
The Implicit Association Test. Journal of Personality and Social Psychology, 74, 1464-1480.

Greenwald, A. G., Nosek, B. A., & Banaji, M. R. (2003). Understanding and Using the Implicit Association Test: 
I. An Improved Scoring Algorithm. Journal of Personality and Social Psychology, 85, 197-216.
 
Stimuli: this script is based on the generic Inquisit IAT template and uses stimuli from Project Implicit's
Skin Tone IAT (images retrieved from: https://osf.io/rf5t4/)

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TASK DESCRIPTION	
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Participants are asked to categorize attributes (e.g. "attractive"; "tragic") and and target items (e.g pictures of light and dark skinned people)
into predetermined categories via keystroke presses. The basic task is to press a left key (E) if an item (e.g. "attractive")
belongs to the category presented on the left (e.g. "Good") and to press the right key (I) if the word (e.g. "tragic") 
belongs to the category ("Bad") presented on the right.
For practice, participants sort items into the target categories "Light Skinned People vs. Dark Skinned People" and the attribute categories "Good vs. Bad".
For the test, participants are asked to sort categories into the paired/combined categories (e.g. 
"Light Skinned People OR Good" on the left vs. "Dark Skinned People OR Bad" on the right). Pairings are reversed for a second test 
(e.g. "Dark Skinned People OR Good" on the left vs. "Light Skinned People OR Bad" on the right). Block order is counterbalanced by groupnumber.	

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DURATION 
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the default set-up of the script takes appr. 5.5 minutes to complete

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DATA FILE INFORMATION 
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The default data stored in the data files are:

(1) Raw data file: 'skintoneiat_raw*.iqdat' (a separate file for each participant)

build:							The specific Inquisit version used (the 'build') that was run
computer.platform:				the platform the script was run on (win/mac/ios/android)
date, time: 					date and time script was run 

subject, group, 				with the current subject/groupnumber
										Note: odd/even groupnumbers balance the order in which 
										hypothesis-compatible/incompatible blocks are run
										odd = compatible - incompatible
										even = incompatible - compatible
										
session:						with the current session id

blockcode, blocknum:			the name and number of the current block (built-in Inquisit variable)
trialcode, trialnum: 			the name and number of the currently recorded trial (built-in Inquisit variable)
									Note: trialnum is a built-in Inquisit variable; it counts all trials run; 
									even those that do not store data to the data file such as feedback trials
									
conditionOrder:					c-ic: consistent -> inconsistent
								ic-c: inconsistent -> consistent									
									
response:						the response key pressed (e.g. 18=E or 23=I)										
								Note: script saves the final and -by design- correct response for each trial
										
correct:						the accuracy of the initial response
										0 = initial response was incorrect and needed to be corrected
										1 = initial response is correct
										
latency:						the latency of the final (correct) response in ms; measured from onset of stim
stimulusnumber:					the number of the current stimulus
stimulusitem:					the currently presented item


Only meaningful for the last row of data in the raw data file (upon completion of IAT):

da:								d-score of the first short blocks
db:								d-score of the second long blocks

d:								overall d-score (non-weighted mean of the 2 d-scores); main DV

								Suggested Interpretation:

											D-score <= -0.65 => "a strong" preference for hypothesis-NONconforming pairings
											D-score < -0.35 => "a moderate" preference for hypothesis-NONconforming pairings
											D-score < -0.15 => "a slight" preference for hypothesis-NONforming pairings																						
											-0.15 <= D-score <= 0.15 "little to no" preference
											D-score > 0.15 => "a slight" preference for hypothesis-conforming pairings
											D-score > 0.35 => "a moderate" preference for hypothesis-conforming pairings
											D-score >= 0.65 => "a strong" preference for hypothesis-conforming pairings

percentcorrect:      			the overall percent correct score of initial responses in test trials of D-score qualifying latencies

propRT300:						the proportion of response latencies < 300ms

excludeCriteriaMet:				1 = yes, exclusion supported per Greenwald et al (2003, p.214, Table 4):
								More than 10% of all response latencies are faster than 300ms
								0 = otherwise
									

(2) Summary data file: 'skintoneiat_summary*.iqdat' (a separate file for each participant)

inquisit.version: 				Inquisit version run
computer.platform:				the platform the script was run on (win/mac/ios/android)
startDate:						date script was run
startTime:						time script was started
subjectid:						assigned subject id number
groupid:						assigned group id number
sessionid:						assigned session id number
elapsedTime:					time it took to run script (in ms); measured from onset to offset of script
completed:						0 = script was not completed (prematurely aborted); 
								1 = script was completed (all conditions run)
								
conditionOrder:					c-ic: consistent -> inconsistent
								ic-c: inconsistent -> consistent								

da:								d-score of the first short blocks
db:								d-score of the second long blocks

d:								overall d-score (non-weighted mean of the 2 d-scores); main DV

								Suggested Interpretation:

											D-score <= -0.65 => "a strong" preference for hypothesis-NONconforming pairings
											D-score < -0.35 => "a moderate" preference for hypothesis-NONconforming pairings
											D-score < -0.15 => "a slight" preference for hypothesis-NONforming pairings																						
											-0.15 <= D-score <= 0.15 "little to no" preference
											D-score > 0.15 => "a slight" preference for hypothesis-conforming pairings
											D-score > 0.35 => "a moderate" preference for hypothesis-conforming pairings
											D-score >= 0.65 => "a strong" preference for hypothesis-conforming pairings

percentcorrect:    				the overall percent correct score of initial responses in test trials of D-score qualifying latencies

propRT300:						the proportion of response latencies < 300ms

excludeCriteriaMet:				1 = yes, exclusion supported per Greenwald et al (2003, p.214, Table 4):
								More than 10% of all response latencies are faster than 300ms
								0 = otherwise
									
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EXPERIMENTAL SET-UP 
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Hypothesis-consistent pairings vs. hypothesis-inconsistent pairings; tested within-subjects in a blocked format
=> order is counterbalanced by groupnumber assignment
odd groupnumbers run: consistent - inconconsistent pairings
even groupnumbers run: inconsistent - consistent pairings

Block Sequence:
1. Target Category sorting training
2. Attribute sorting training
3. 1. Test Block of hypothesis-consistent* pairings with 20 trials (half the participant start with inconsistent pairings)
4. 2. Test Block of hypothesis-consistent pairings with 40 trials
5. Target Category sorting training with targets switching sides
6. 1. Test Block of hypothesis-inconsistent pairings with 20 trials
7. 2. Test Block of hypothesis-inconsistent pairings with 40 trials

In all Test Blocks:
* attributes and targets alternate
* attributes as well as targets are randomly selected without replacement

Trial Sequence:
Target -> until correct response -> ISI: 250ms (default)-> Target....

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STIMULI
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Stimuli can be edited under section Editable Stimuli

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INSTRUCTIONS 
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* start instruction page is provided as an html page. It automatically adapts to different images and category labels UNLESS
the number of attributes and/or targets have been changed. In this case, changes have to be 
made to file "intro_iat.htm", so that the correct number of items are presented in the overview table.

Example: instead of 8 words for target A, only 5 should be presented:

in file "intro_iat.htm":
change:
			<td><%item.targetA.item(1)%>, <%item.targetA.item(2)%>, <%item.targetA.item(3)%>, <%item.targetA.item(4)%>, 
				<%item.targetA.item(5)%>, <%item.targetA.item(6)%>, <%item.targetA.item(7)%>, <%item.targetA.item(8)%>
			</td>

To:
			<td><%item.targetA.item(1)%>, <%item.targetA.item(2)%>, <%item.targetA.item(3)%>, <%item.targetA.item(4)%>, 
				<%item.targetA.item(5)%>
			</td>

* item.instructions under section 'Editable Instructions' contains the the trial instructions
The instructions adapt automatically if different attributes and targets are used.

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EDITABLE CODE 
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check below for (relatively) easily editable parameters, stimuli, instructions etc. 
Keep in mind that you can use this script as a template and therefore always "mess" with the entire code 
to further customize your experiment.

The parameters you can change are:

/showsummaryfeedback:		set parameter showsummaryfeedback = true to display summary feedback to participants at the end (default)
							set parameter showsummaryfeedback = false if no summary feedback should be presented to participants
							
/ISI:						interstimulus interval (in ms) (default: 250ms)