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								Dropout Study / Test Procedure
SCRIPT INFO

Script Author: David Nitz (dave@millisecond.com) for Millisecond Software, LLC
last updated: 01-20-2016 by K.Borchert (katjab@millisecond.com) for Millisecond Software LLC

Copyright © 01-20-2016 Millisecond Software


BACKGROUND INFO

											*Purpose*
	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.


											  *Task*
	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.											  


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

(1) Raw data file: 'KarpickeRoediger2008_raw*.iqdat' (a separate file for each participant)

build:										Inquisit build
computer.platform:							the platform the script was run on
date, time, subject, group:					date and time script was run with the current subject/groupnumber 
subjectid:									A unique participant identifier collected at task onset.
condition:									The assigned experimental condition as collected at task onset: 1=ST, 2=SnT, 3=STn, 4=SnTn.
session:									The current session number as collected at task onset.
taskphase:									Name of the current task phase ("study phase", "test phase", "math phase", "delayed test phase").
blockcode, blocknum:						the name and number of the current block
trialcode, trialnum: 						the name and number of the currently recorded trial
												(Note: not all trials that are run might record data) 
stimulusitem:								the presented stimuli in order of trial presentation
response:									the participant's 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
trialcount:									Number of trials run in the current study or test period.
ncorrect:									Number of correct responses in the current test period.
itemnumber:									Holds the unique itemnumber of the currently selected pair. Used for proper item selection and validation, scoring, etc.
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: 	'expressions.swahili' and '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)

script.startdate:							date script was run
script.starttime:							time script was started
script.subjectid:							subject id number
script.groupid:								group id number
script.elapsedtime:							time it took to run script (in ms)
computer.platform:							the platform the script was run on
/completed:									0 = script was not completed (prematurely aborted); 1 = script was completed (all conditions run)
subjectid:									A unique participant identifier collected at task onset.
condition:									The assigned experimental condition as collected at task onset: 1=ST, 2=SnT, 3=STn, 4=SnTn.
session:									The current session number as collected at task onset.
taskphase:									Name of the current task phase ("study phase", "test phase", "math phase", "delayed test phase").
trialcount:									Number of trials run in the current study or test period.
ncorrect:									Number of correct responses in the current test period.


EXPERIMENTAL SET-UP
* 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):
(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. 

STIMULI
see section Editable Stimuli

INSTRUCTIONS
see section Editable Instruction

EDITABLE CODE:
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.

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