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								Word List Learning with Word Dropout Procedure
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Script Author: David Nitz (dave@millisecond.com) for Millisecond Software, LLC
last updated:  06-30-2020 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Script Copyright © 06-30-2020 Millisecond Software

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BACKGROUND INFO 	
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	This script implements the learning experiment described in:
	
	Karpicke, J. D. & Roediger, H. L. (2008). The critical importance of retrieval for learning.
	Science, 319, 966-968.

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TASK DESCRIPTION	
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	This is a learning experiment. Participants are presented a total of 40 Swahili-English word
	pairs one at a time. Subjects are required to learn these items so that they are able to recall
	the correct English translation given the Swahili word. There are a total of 4 study and 4 test
	periods and an intermittent distracter task. There are four experimental conditions:
	
	(1) ST
	Subjects study the whole list of 40 items in each study period.
	Subjects are tested on the whole list of 40 items in each test period.

	(2) SnT
	Subjects study only those items they have not recalled previously.
	Subjects are tested on the whole list of 40 items in each test period.
	
	(3) STn
	Subjects study the whole list of 40 items in each study period.
	Subjects are tested only on those items they have not recalled previously.
	
	(4) SnTn
	Subjects study only those items they have not recalled previously.
	Subjects are tested only on those items they have not recalled previously.

	Please refer to the cited source(s) for a more detailed description of the procedure.											  

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DURATION 
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depends on selected condition:
the default set-up of the ST condition takes appr. 40 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: 'karpickeroediger2008_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
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. Thus, trialnum 
										may not reflect the number of main trials run per block. 
												
values.condition:				The assigned experimental condition as collected at task onset: 1=ST, 2=SnT, 3=STn, 4=SnTn.
values.taskphase:				Name of the current task phase ("study phase", "test phase", "math phase", "delayed test phase").
												
response:						the participant's entered response
expressions.resptolower:		converts participants' typed answers to lowercase in order to ensure accurate 
								but not overly strict scoring of correct and incorrect responses.
									
correct:						the correctness of the response (1 = correct; 0 = incorrect)
error:							1 = error; 0 = no error
numcorrect:						running total of correct responses in the current block

latency: 						the response latency (in ms) 
								for openended responses: measured until "next" box is clicked
							
openended.testtrial.firstcharlatency:		latency (in ms) measured until input of first character
openended.testtrial.lastcharlatency: 		latency (in ms) measured until input of last character

values.trialcount:				Number of trials run in the current study or test period.
values.ncorrect:				Number of correct responses in the current test period.
values.itemnumber:				Holds the unique itemnumber of the currently selected pair. Used for proper item selection and validation, scoring, etc.
values.itemstate:				Encodes whether a given item is active (1) or inactive (0) in the current study or test period (-> 'trial.itemselect', 'list.studystate','list.teststate').
expressions.swahili/expressions.english: 		return the currently used Swahili-English word pair for data logging purposes.
text.mathproblem.currentitem:					the currently presented math problems



(2) Summary data file: 'karpickeroediger2008_summary*.iqdat' (a separate file for each participant)

computer.platform:				the platform the script was run on (win/mac/ios/android)
script.startdate:				date script was run
script.starttime:				time script was started
script.subjectid:				assigned subject id number
script.groupid:					assigned group id number
script.sessionid:				assigned session id number
script.elapsedtime:				time it took to run script (in ms); measured from onset to offset of script
script.completed:				0 = script was not completed (prematurely aborted); 
								1 = script was completed (all conditions run)

values.condition:				The assigned experimental condition as collected at task onset: 1=ST, 2=SnT, 3=STn, 4=SnTn.
values.taskphase:				Name of the current task phase ("study phase", "test phase", "math phase", "delayed test phase").
values.trialcount:				Number of trials run in the current study or test period.
values.ncorrect:				Number of correct responses in the current test period.


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EXPERIMENTAL SET-UP 
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* 4 different experimental conditions:
	(1) ST
	Subjects study the whole list of 40 items in each study period.
	Subjects are tested on the whole list of 40 items in each test period.

	(2) SnT
	Subjects study only those items they have not recalled previously.
	Subjects are tested on the whole list of 40 items in each test period.
	
	(3) STn
	Subjects study the whole list of 40 items in each study period.
	Subjects are tested only on those items they have not recalled previously.
	
	(4) SnTn
	Subjects study only those items they have not recalled previously.
	Subjects are tested only on those items they have not recalled previously.
	
* Two Sessions (1 week apart): Session ID is entered at start of script together with Subject and Group id
(1) Initial: four study-distractor-test periods of 40 Swahili-English word pairs;
Phase ends with participants predicting their performance in the follow-up session
(2) Follow-up: a single test period is completed one week after the initial session. 

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STIMULI
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see section Editable Stimuli

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INSTRUCTIONS 
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see section Editable Instruction

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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:

	studytimeout:				Display duration during study trials. Default: 5000 ms.
	testtimeout:				Timeout for test trials. Default: 8000 ms.
	delayedtesttimeout:			Timeout for the delayed test trials (2nd session). Default: 15000 ms.
	distractertimeout:			Global timeout for the distracter block. Default: 30000 ms.
	posttrialdelay:				Variable posttrial delay for study and test trials. Default: 500 ms.
	
	debugmode:					1 = debuginfo is displayed on screen
								0 = script runs in testmode; no debuginfo is displayed