Shuffle items in list to use same order of stimuli throughout experiment


Shuffle items in list to use same order of stimuli throughout...

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Tahwan
Tahwan
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After the fast reply to my last question I am trying it again. I am very suprised I couldn't find a previous post asking the same thing, because it appears to me to be a standard feature I am looking for:
I have four stimuli. I want the order of the stimuli randomized per subject at the beginning of the experiment (counterbalancing between subjects). Then I want to use the same order of stimuli at various points of the experiment. 
So lets say I have four stimuli:

<item Simuli_Portraits>
/1 = "flower1.jpg"
/2 = "flower2.jpg"
/3 = "flower3.jpg"
/4 = "flower4.jpg"
</item>

I could call a specific item in "picture" using select:
<picture Portrait1>
/ items = Simuli_Portraits
/ select = 1
</picture>

All I would need is a shuffeled array of numbers that I could call one by one via select, let's say
/select = order_stimuli(1), where order_stimuli is a random order of the numbers 1-4

I can also create a sequence of numbers via list:
<list order_stimuli>
/ items = (1,4)
/ selectionmode = random
/ selectionrate = experiment
</list>

Yet, what I don't understand is whether this really provides me a list of numbers or only one number. All I need is a function that shuffles an array of numbers, in which I can call the x-th element of the array.
I was also thinking about some workaround methods:
1. Manually creating all possible orders (a list of items with all combination "1234", "1243, "1324", ..., "4321") as randomly choosing one. Here again I have the problem that I don't know how to call the x-th element of the string/number/array for select in the picture function.
2. Using some complicated randomization with branches at the beginning of the experiment to create a randomized order in items, also not having a clue how that could work.

I am very much into the logic of (dynamical) indexing that I might miss the very obvious solution on how to keep randomization consistent throughout multiple blocks of the experiment. Thank you for your help!


Dave
Dave
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Tahwan - Tuesday, April 17, 2018
After the fast reply to my last question I am trying it again. I am very suprised I couldn't find a previous post asking the same thing, because it appears to me to be a standard feature I am looking for:
I have four stimuli. I want the order of the stimuli randomized per subject at the beginning of the experiment (counterbalancing between subjects). Then I want to use the same order of stimuli at various points of the experiment. 
So lets say I have four stimuli:

<item Simuli_Portraits>
/1 = "flower1.jpg"
/2 = "flower2.jpg"
/3 = "flower3.jpg"
/4 = "flower4.jpg"
</item>

I could call a specific item in "picture" using select:
<picture Portrait1>
/ items = Simuli_Portraits
/ select = 1
</picture>

All I would need is a shuffeled array of numbers that I could call one by one via select, let's say
/select = order_stimuli(1), where order_stimuli is a random order of the numbers 1-4

I can also create a sequence of numbers via list:
<list order_stimuli>
/ items = (1,4)
/ selectionmode = random
/ selectionrate = experiment
</list>

Yet, what I don't understand is whether this really provides me a list of numbers or only one number. All I need is a function that shuffles an array of numbers, in which I can call the x-th element of the array.
I was also thinking about some workaround methods:
1. Manually creating all possible orders (a list of items with all combination "1234", "1243, "1324", ..., "4321") as randomly choosing one. Here again I have the problem that I don't know how to call the x-th element of the string/number/array for select in the picture function.
2. Using some complicated randomization with branches at the beginning of the experiment to create a randomized order in items, also not having a clue how that could work.

I am very much into the logic of (dynamical) indexing that I might miss the very obvious solution on how to keep randomization consistent throughout multiple blocks of the experiment. Thank you for your help!


What you do is this: Have one <list> containing the values 1 to 4 set to random selection. Have another empty <list> set to sequential selection. Sample four values from the 1st list /onexptbegin and store them in the empty list. You now have a fixed randomly generated sequence which you can use for selection as needed. In a nutshell:


<list rand>
/ poolsize = 4
/ selectionrate = always
/ selectionmode = random
/ replace = false
</list>

<list fixedseq>
/ selectionmode = sequence
</list>

<expt>
/ onexptbegin = [
    list.fixedseq.appenditem(list.rand.nextindex);
    list.fixedseq.appenditem(list.rand.nextindex);
    list.fixedseq.appenditem(list.rand.nextindex);
    list.fixedseq.appenditem(list.rand.nextindex);
]
/ blocks = [1=myblock]
</expt>


<block myblock>
/ trials = [1-16 = mytrial]
</block>

<trial mytrial>
/ stimulusframes = [1=mytext]
/ validresponse = (57)
</trial>

<text mytext>
/ items = myitems
/ select = list.fixedseq.nextvalue
</text>

<item myitems>
/ 1 = "A"
/ 2 = "B"
/ 3 = "C"
/ 4 = "D"
</item>

Hope this helps.

Dave
Dave
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Dave - Tuesday, April 17, 2018
Tahwan - Tuesday, April 17, 2018
After the fast reply to my last question I am trying it again. I am very suprised I couldn't find a previous post asking the same thing, because it appears to me to be a standard feature I am looking for:
I have four stimuli. I want the order of the stimuli randomized per subject at the beginning of the experiment (counterbalancing between subjects). Then I want to use the same order of stimuli at various points of the experiment. 
So lets say I have four stimuli:

<item Simuli_Portraits>
/1 = "flower1.jpg"
/2 = "flower2.jpg"
/3 = "flower3.jpg"
/4 = "flower4.jpg"
</item>

I could call a specific item in "picture" using select:
<picture Portrait1>
/ items = Simuli_Portraits
/ select = 1
</picture>

All I would need is a shuffeled array of numbers that I could call one by one via select, let's say
/select = order_stimuli(1), where order_stimuli is a random order of the numbers 1-4

I can also create a sequence of numbers via list:
<list order_stimuli>
/ items = (1,4)
/ selectionmode = random
/ selectionrate = experiment
</list>

Yet, what I don't understand is whether this really provides me a list of numbers or only one number. All I need is a function that shuffles an array of numbers, in which I can call the x-th element of the array.
I was also thinking about some workaround methods:
1. Manually creating all possible orders (a list of items with all combination "1234", "1243, "1324", ..., "4321") as randomly choosing one. Here again I have the problem that I don't know how to call the x-th element of the string/number/array for select in the picture function.
2. Using some complicated randomization with branches at the beginning of the experiment to create a randomized order in items, also not having a clue how that could work.

I am very much into the logic of (dynamical) indexing that I might miss the very obvious solution on how to keep randomization consistent throughout multiple blocks of the experiment. Thank you for your help!


What you do is this: Have one <list> containing the values 1 to 4 set to random selection. Have another empty <list> set to sequential selection. Sample four values from the 1st list /onexptbegin and store them in the empty list. You now have a fixed randomly generated sequence which you can use for selection as needed. In a nutshell:


<list rand>
/ poolsize = 4
/ selectionrate = always
/ selectionmode = random
/ replace = false
</list>

<list fixedseq>
/ selectionmode = sequence
</list>

<expt>
/ onexptbegin = [
    list.fixedseq.appenditem(list.rand.nextindex);
    list.fixedseq.appenditem(list.rand.nextindex);
    list.fixedseq.appenditem(list.rand.nextindex);
    list.fixedseq.appenditem(list.rand.nextindex);
]
/ blocks = [1=myblock]
</expt>


<block myblock>
/ trials = [1-16 = mytrial]
</block>

<trial mytrial>
/ stimulusframes = [1=mytext]
/ validresponse = (57)
</trial>

<text mytext>
/ items = myitems
/ select = list.fixedseq.nextvalue
</text>

<item myitems>
/ 1 = "A"
/ 2 = "B"
/ 3 = "C"
/ 4 = "D"
</item>

Hope this helps.

Oh, and if you have several fixed orders you wish to counterbalance between subjects, you can do this like so, by essentially nesting lists:

<list orders>
/ items = (list.order1.nextvalue, list.order2.nextvalue)
/ selectionmode = values.ordernumber
</list>

<list order1>
/ items = (1,2,3,4)
/ selectionmode = sequence
</list>

<list order2>
/ items = (4,3,2,1)
/ selectionmode = sequence
</list>

<values>
/ ordernumber = 1
</values>


<expt>
/ onexptbegin = [
    values.ordernumber = 1;
]
/ blocks = [1=myblock]
/ subjects = (1 of 2)
/ groupassignment = groupnumber
</expt>

<expt>
/ onexptbegin = [
    values.ordernumber = 2;
]
/ blocks = [1=myblock]
/ subjects = (2 of 2)
/ groupassignment = groupnumber
</expt>


<block myblock>
/ trials = [1-16 = mytrial]
</block>

<trial mytrial>
/ stimulusframes = [1=mytext]
/ validresponse = (57)
</trial>

<text mytext>
/ items = myitems
/ select = list.orders.nextvalue
</text>

<item myitems>
/ 1 = "A"
/ 2 = "B"
/ 3 = "C"
/ 4 = "D"
</item>

Tahwan
Tahwan
New Member
New Member (24 reputation)New Member (24 reputation)New Member (24 reputation)New Member (24 reputation)New Member (24 reputation)New Member (24 reputation)New Member (24 reputation)New Member (24 reputation)New Member (24 reputation)

Group: Forum Members
Posts: 5, Visits: 20
Dave - Tuesday, April 17, 2018
Dave - Tuesday, April 17, 2018
Tahwan - Tuesday, April 17, 2018
After the fast reply to my last question I am trying it again. I am very suprised I couldn't find a previous post asking the same thing, because it appears to me to be a standard feature I am looking for:
I have four stimuli. I want the order of the stimuli randomized per subject at the beginning of the experiment (counterbalancing between subjects). Then I want to use the same order of stimuli at various points of the experiment. 
So lets say I have four stimuli:

<item Simuli_Portraits>
/1 = "flower1.jpg"
/2 = "flower2.jpg"
/3 = "flower3.jpg"
/4 = "flower4.jpg"
</item>

I could call a specific item in "picture" using select:
<picture Portrait1>
/ items = Simuli_Portraits
/ select = 1
</picture>

All I would need is a shuffeled array of numbers that I could call one by one via select, let's say
/select = order_stimuli(1), where order_stimuli is a random order of the numbers 1-4

I can also create a sequence of numbers via list:
<list order_stimuli>
/ items = (1,4)
/ selectionmode = random
/ selectionrate = experiment
</list>

Yet, what I don't understand is whether this really provides me a list of numbers or only one number. All I need is a function that shuffles an array of numbers, in which I can call the x-th element of the array.
I was also thinking about some workaround methods:
1. Manually creating all possible orders (a list of items with all combination "1234", "1243, "1324", ..., "4321") as randomly choosing one. Here again I have the problem that I don't know how to call the x-th element of the string/number/array for select in the picture function.
2. Using some complicated randomization with branches at the beginning of the experiment to create a randomized order in items, also not having a clue how that could work.

I am very much into the logic of (dynamical) indexing that I might miss the very obvious solution on how to keep randomization consistent throughout multiple blocks of the experiment. Thank you for your help!


What you do is this: Have one <list> containing the values 1 to 4 set to random selection. Have another empty <list> set to sequential selection. Sample four values from the 1st list /onexptbegin and store them in the empty list. You now have a fixed randomly generated sequence which you can use for selection as needed. In a nutshell:


<list rand>
/ poolsize = 4
/ selectionrate = always
/ selectionmode = random
/ replace = false
</list>

<list fixedseq>
/ selectionmode = sequence
</list>

<expt>
/ onexptbegin = [
    list.fixedseq.appenditem(list.rand.nextindex);
    list.fixedseq.appenditem(list.rand.nextindex);
    list.fixedseq.appenditem(list.rand.nextindex);
    list.fixedseq.appenditem(list.rand.nextindex);
]
/ blocks = [1=myblock]
</expt>


<block myblock>
/ trials = [1-16 = mytrial]
</block>

<trial mytrial>
/ stimulusframes = [1=mytext]
/ validresponse = (57)
</trial>

<text mytext>
/ items = myitems
/ select = list.fixedseq.nextvalue
</text>

<item myitems>
/ 1 = "A"
/ 2 = "B"
/ 3 = "C"
/ 4 = "D"
</item>

Hope this helps.

Oh, and if you have several fixed orders you wish to counterbalance between subjects, you can do this like so, by essentially nesting lists:

<list orders>
/ items = (list.order1.nextvalue, list.order2.nextvalue)
/ selectionmode = values.ordernumber
</list>

<list order1>
/ items = (1,2,3,4)
/ selectionmode = sequence
</list>

<list order2>
/ items = (4,3,2,1)
/ selectionmode = sequence
</list>

<values>
/ ordernumber = 1
</values>


<expt>
/ onexptbegin = [
    values.ordernumber = 1;
]
/ blocks = [1=myblock]
/ subjects = (1 of 2)
/ groupassignment = groupnumber
</expt>

<expt>
/ onexptbegin = [
    values.ordernumber = 2;
]
/ blocks = [1=myblock]
/ subjects = (2 of 2)
/ groupassignment = groupnumber
</expt>


<block myblock>
/ trials = [1-16 = mytrial]
</block>

<trial mytrial>
/ stimulusframes = [1=mytext]
/ validresponse = (57)
</trial>

<text mytext>
/ items = myitems
/ select = list.orders.nextvalue
</text>

<item myitems>
/ 1 = "A"
/ 2 = "B"
/ 3 = "C"
/ 4 = "D"
</item>

Thank you very much for your fast response. Unfortunately it is not solving my problem. "/ select = list.orders.nextvalue" is not working for me, because I do not always want the "next value". I want participants to judge 4 images. First regarding one trait, then regarding another trait and so on. The participant has several options to get additional information, branching to several different pages/trials. Easiest would be a function "/ select = list.orders.1", calling the first number of the fixed sequence list "fixedseq" whenever I need to. Working with nextvalue would drive me crazy, because I want to call the same number in different blocks.

A different idea: I could create a list of all combinations as strings, call the n-th position via some regex (if possible), convert that string to a number that could be used for / select". For example would "/a{2}/" extract the third value of a string "3412", providing me a "1". But I neither know whether Regey works nor whether it is possible to to use/convert the string to a number usable by "/ select".

Tahwan
Tahwan
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Group: Forum Members
Posts: 5, Visits: 20
Dave - Tuesday, April 17, 2018
Dave - Tuesday, April 17, 2018
Tahwan - Tuesday, April 17, 2018
After the fast reply to my last question I am trying it again. I am very suprised I couldn't find a previous post asking the same thing, because it appears to me to be a standard feature I am looking for:
I have four stimuli. I want the order of the stimuli randomized per subject at the beginning of the experiment (counterbalancing between subjects). Then I want to use the same order of stimuli at various points of the experiment. 
So lets say I have four stimuli:

<item Simuli_Portraits>
/1 = "flower1.jpg"
/2 = "flower2.jpg"
/3 = "flower3.jpg"
/4 = "flower4.jpg"
</item>

I could call a specific item in "picture" using select:
<picture Portrait1>
/ items = Simuli_Portraits
/ select = 1
</picture>

All I would need is a shuffeled array of numbers that I could call one by one via select, let's say
/select = order_stimuli(1), where order_stimuli is a random order of the numbers 1-4

I can also create a sequence of numbers via list:
<list order_stimuli>
/ items = (1,4)
/ selectionmode = random
/ selectionrate = experiment
</list>

Yet, what I don't understand is whether this really provides me a list of numbers or only one number. All I need is a function that shuffles an array of numbers, in which I can call the x-th element of the array.
I was also thinking about some workaround methods:
1. Manually creating all possible orders (a list of items with all combination "1234", "1243, "1324", ..., "4321") as randomly choosing one. Here again I have the problem that I don't know how to call the x-th element of the string/number/array for select in the picture function.
2. Using some complicated randomization with branches at the beginning of the experiment to create a randomized order in items, also not having a clue how that could work.

I am very much into the logic of (dynamical) indexing that I might miss the very obvious solution on how to keep randomization consistent throughout multiple blocks of the experiment. Thank you for your help!


What you do is this: Have one <list> containing the values 1 to 4 set to random selection. Have another empty <list> set to sequential selection. Sample four values from the 1st list /onexptbegin and store them in the empty list. You now have a fixed randomly generated sequence which you can use for selection as needed. In a nutshell:


<list rand>
/ poolsize = 4
/ selectionrate = always
/ selectionmode = random
/ replace = false
</list>

<list fixedseq>
/ selectionmode = sequence
</list>

<expt>
/ onexptbegin = [
    list.fixedseq.appenditem(list.rand.nextindex);
    list.fixedseq.appenditem(list.rand.nextindex);
    list.fixedseq.appenditem(list.rand.nextindex);
    list.fixedseq.appenditem(list.rand.nextindex);
]
/ blocks = [1=myblock]
</expt>


<block myblock>
/ trials = [1-16 = mytrial]
</block>

<trial mytrial>
/ stimulusframes = [1=mytext]
/ validresponse = (57)
</trial>

<text mytext>
/ items = myitems
/ select = list.fixedseq.nextvalue
</text>

<item myitems>
/ 1 = "A"
/ 2 = "B"
/ 3 = "C"
/ 4 = "D"
</item>

Hope this helps.

Oh, and if you have several fixed orders you wish to counterbalance between subjects, you can do this like so, by essentially nesting lists:

<list orders>
/ items = (list.order1.nextvalue, list.order2.nextvalue)
/ selectionmode = values.ordernumber
</list>

<list order1>
/ items = (1,2,3,4)
/ selectionmode = sequence
</list>

<list order2>
/ items = (4,3,2,1)
/ selectionmode = sequence
</list>

<values>
/ ordernumber = 1
</values>


<expt>
/ onexptbegin = [
    values.ordernumber = 1;
]
/ blocks = [1=myblock]
/ subjects = (1 of 2)
/ groupassignment = groupnumber
</expt>

<expt>
/ onexptbegin = [
    values.ordernumber = 2;
]
/ blocks = [1=myblock]
/ subjects = (2 of 2)
/ groupassignment = groupnumber
</expt>


<block myblock>
/ trials = [1-16 = mytrial]
</block>

<trial mytrial>
/ stimulusframes = [1=mytext]
/ validresponse = (57)
</trial>

<text mytext>
/ items = myitems
/ select = list.orders.nextvalue
</text>

<item myitems>
/ 1 = "A"
/ 2 = "B"
/ 3 = "C"
/ 4 = "D"
</item>

Sorry, in fact it does work, because I can call the x-th element of the list via list.fixedseq.x, for example list.fixedseq.2. Thank you very much!

GO


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