Linked/ conditioned consecutive randomization


Linked/ conditioned consecutive randomization

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Rebsu
Rebsu
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Dear all,

I'm currently pretty stuck at the randomization of my experiment. There are two main problems:

1) I have two picture pools, <item Suchbild> with items from SB1A, SB1B, SB2A...SB5B, and <item Zielreiz> with 5 pictures ZR1..ZR5. I want to randomly present one of the Zielreiz first, then present a Suchbild. The problem is that I have to link the Zielreiz to the Suchbilder. So, if ZR1 is shown, SB1A or SB1B has to be shown after, for ZR2 it has to be SB2A or SB2B etc. I thought adding a copy of each ZR to the item list, so that there is a clear one-to-one connection for each Zielreiz and Suchbild. 
Now my beginner's question is, is there a "if..then" command or any other way I gotta work around the issue? (And is it correct to set the randomization at the <picture..> level, not the <trial..>?)

<item Zielreiz>
/1 = "ZR1.jpg"
/2 = "ZR2.jpg"
/3 = "ZR3.jpg"
/4 = "ZR4.jpg"
/5 = "ZR5.jpg"
</item>

<picture Zielreiz>
/items = Zielreiz
/select = noreplace
/position = (50, 50)
</picture>

<item Suchbild>
/1 = "SB1A.jpg"
/2 = "SB1B.jpg"
/3 = "SB2A.jpg"
/4 = "SB2B.jpg"
/5 = "SB3A.jpg"
/6 = "SB3B.jpg"
/7 = "SB4A.jpg"
/8 = "SB4B.jpg"
/9 = "SB5A.jpg"
/10 = "SB5B.jpg"
</item>

<picture Suchbild>
/Items = Suchbild
/select = if ....
</picture>

2) A third picture pool, <item Alternative> with NA1..NA5 should be shown after each ZRx-SBxx-trial. My problem is, that I have to show the same picture twice, so NAx for 1 sec, then a fixation cross, then the same NAx for another five seconds. My idea is to set a second Alternative 2, which selects the current Alternative (1) picture. Does this work or is there a possibility to set the /select = noreplace to pick a picture twice, then go on with selecting a different one?

Rudimentally, it would look like this:
<item Alternative>
/1 = "NA1.jpg"
/2 = "NA2.jpg"
/3 = "NA3.jpg"
/4 = "NA4.jpg"
/5 = "NA5.jpg"
</item>

<picture Alternative>
/items = Alternative
/select = noreplace
/position = (50, 50)
</picture>

<picture Alternative 2>
/items = Alternative
/select = current
/position = (50, 50)
</picture>

Thank you so much in advance!
Best regards,
rebsu
Dave
Dave
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Rebsu - Tuesday, May 7, 2019
Dear all,

I'm currently pretty stuck at the randomization of my experiment. There are two main problems:

1) I have two picture pools, <item Suchbild> with items from SB1A, SB1B, SB2A...SB5B, and <item Zielreiz> with 5 pictures ZR1..ZR5. I want to randomly present one of the Zielreiz first, then present a Suchbild. The problem is that I have to link the Zielreiz to the Suchbilder. So, if ZR1 is shown, SB1A or SB1B has to be shown after, for ZR2 it has to be SB2A or SB2B etc. I thought adding a copy of each ZR to the item list, so that there is a clear one-to-one connection for each Zielreiz and Suchbild. 
Now my beginner's question is, is there a "if..then" command or any other way I gotta work around the issue? (And is it correct to set the randomization at the <picture..> level, not the <trial..>?)

<item Zielreiz>
/1 = "ZR1.jpg"
/2 = "ZR2.jpg"
/3 = "ZR3.jpg"
/4 = "ZR4.jpg"
/5 = "ZR5.jpg"
</item>

<picture Zielreiz>
/items = Zielreiz
/select = noreplace
/position = (50, 50)
</picture>

<item Suchbild>
/1 = "SB1A.jpg"
/2 = "SB1B.jpg"
/3 = "SB2A.jpg"
/4 = "SB2B.jpg"
/5 = "SB3A.jpg"
/6 = "SB3B.jpg"
/7 = "SB4A.jpg"
/8 = "SB4B.jpg"
/9 = "SB5A.jpg"
/10 = "SB5B.jpg"
</item>

<picture Suchbild>
/Items = Suchbild
/select = if ....
</picture>

2) A third picture pool, <item Alternative> with NA1..NA5 should be shown after each ZRx-SBxx-trial. My problem is, that I have to show the same picture twice, so NAx for 1 sec, then a fixation cross, then the same NAx for another five seconds. My idea is to set a second Alternative 2, which selects the current Alternative (1) picture. Does this work or is there a possibility to set the /select = noreplace to pick a picture twice, then go on with selecting a different one?

Rudimentally, it would look like this:
<item Alternative>
/1 = "NA1.jpg"
/2 = "NA2.jpg"
/3 = "NA3.jpg"
/4 = "NA4.jpg"
/5 = "NA5.jpg"
</item>

<picture Alternative>
/items = Alternative
/select = noreplace
/position = (50, 50)
</picture>

<picture Alternative 2>
/items = Alternative
/select = current
/position = (50, 50)
</picture>

Thank you so much in advance!
Best regards,
rebsu

If I understand you correctly, you'll simply want to pair your "Suchbild" <picture> elements to your "Zielreiz" <picture>:

https://www.millisecond.com/support/docs/v4/html/howto/howtopairs.htm

In a nutshell, I'd do something like this:

<values>
/ zielitem = 1
/ suchitem = 1
</values>

<block exampleblock>
/ trials = [1-5 = exampletrial]
</block>

<trial exampletrial>
/ ontrialbegin = [values.zielitem = list.zr_itemnumbers.nextindex;
values.suchitem = values.zielitem + list.version.nextvalue;]
/ stimulustimes = [0=zielreiz; 2000=suchbild]
/ validresponse = (57)
</trial>

<list zr_itemnumbers>
/ poolsize = 5
</list>

<list version>
/ items = (0,5)
/ replace = true
</list>

<item Zielreiz>
/1 = "ZR1.jpg"
/2 = "ZR2.jpg"
/3 = "ZR3.jpg"
/4 = "ZR4.jpg"
/5 = "ZR5.jpg"
</item>

<text Zielreiz>
/items = Zielreiz
/select = values.zielitem
/position = (50, 50)
</text>

<item Suchbild>
/1 = "SB1A.jpg"
/2 = "SB2A.jpg"
/3 = "SB3A.jpg"
/4 = "SB4A.jpg"
/5 = "SB5A.jpg"

/6 = "SB1B.jpg"
/7 = "SB2B.jpg"
/8 = "SB3B.jpg"
/9 = "SB4B.jpg"
/10 = "SB5B.jpg"
</item>

<text suchbild>
/ items = suchbild
/ select = values.suchitem
</text>

Or, if you'd rather keep things a bit simpler, you could set up two separate trials (one for version a, one for version b) and then sample from those trials randomly at the block-level:

<block exampleblock>
/ trials = [1-5 = replace(a,b)]
</block>

<trial a>
/ stimulustimes = [0=zielreiz; 2000=suchbilda]
/ validresponse = (57)
</trial>

<trial b>
/ stimulustimes = [0=zielreiz; 2000=suchbildb]
/ validresponse = (57)
</trial>

<item Zielreiz>
/1 = "ZR1.jpg"
/2 = "ZR2.jpg"
/3 = "ZR3.jpg"
/4 = "ZR4.jpg"
/5 = "ZR5.jpg"
</item>

<text Zielreiz>
/items = Zielreiz
/select = noreplace
/position = (50, 50)
</text>

<item SuchbildA>
/1 = "SB1A.jpg"
/2 = "SB2A.jpg"
/3 = "SB3A.jpg"
/4 = "SB4A.jpg"
/5 = "SB5A.jpg"
</item>

<item SuchbildB>
/1 = "SB1B.jpg"
/2 = "SB2B.jpg"
/3 = "SB3B.jpg"
/4 = "SB4B.jpg"
/5 = "SB5B.jpg"
</item>

<text suchbildA>
/ items = suchbildA
/ select = text.zielreiz.currentindex
</text>

<text suchbildB>
/ items = suchbildB
/ select = text.zielreiz.currentindex
</text>

And if you want some balance between versions (e.g. either 3 trials of version A and 2 trials of version B or vice versa), you can do

<block exampleblock>
/ trials = [1-4 = noreplace(a,b); 5 = noreplace(a,b)]
</block>

Edited
2 Weeks Ago by Dave
Rebsu
Rebsu
New Member
New Member (16 reputation)New Member (16 reputation)New Member (16 reputation)New Member (16 reputation)New Member (16 reputation)New Member (16 reputation)New Member (16 reputation)New Member (16 reputation)New Member (16 reputation)

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Posts: 2, Visits: 11
Dave - Tuesday, May 7, 2019
Rebsu - Tuesday, May 7, 2019
Dear all,

I'm currently pretty stuck at the randomization of my experiment. There are two main problems:

1) I have two picture pools, <item Suchbild> with items from SB1A, SB1B, SB2A...SB5B, and <item Zielreiz> with 5 pictures ZR1..ZR5. I want to randomly present one of the Zielreiz first, then present a Suchbild. The problem is that I have to link the Zielreiz to the Suchbilder. So, if ZR1 is shown, SB1A or SB1B has to be shown after, for ZR2 it has to be SB2A or SB2B etc. I thought adding a copy of each ZR to the item list, so that there is a clear one-to-one connection for each Zielreiz and Suchbild. 
Now my beginner's question is, is there a "if..then" command or any other way I gotta work around the issue? (And is it correct to set the randomization at the <picture..> level, not the <trial..>?)

<item Zielreiz>
/1 = "ZR1.jpg"
/2 = "ZR2.jpg"
/3 = "ZR3.jpg"
/4 = "ZR4.jpg"
/5 = "ZR5.jpg"
</item>

<picture Zielreiz>
/items = Zielreiz
/select = noreplace
/position = (50, 50)
</picture>

<item Suchbild>
/1 = "SB1A.jpg"
/2 = "SB1B.jpg"
/3 = "SB2A.jpg"
/4 = "SB2B.jpg"
/5 = "SB3A.jpg"
/6 = "SB3B.jpg"
/7 = "SB4A.jpg"
/8 = "SB4B.jpg"
/9 = "SB5A.jpg"
/10 = "SB5B.jpg"
</item>

<picture Suchbild>
/Items = Suchbild
/select = if ....
</picture>

2) A third picture pool, <item Alternative> with NA1..NA5 should be shown after each ZRx-SBxx-trial. My problem is, that I have to show the same picture twice, so NAx for 1 sec, then a fixation cross, then the same NAx for another five seconds. My idea is to set a second Alternative 2, which selects the current Alternative (1) picture. Does this work or is there a possibility to set the /select = noreplace to pick a picture twice, then go on with selecting a different one?

Rudimentally, it would look like this:
<item Alternative>
/1 = "NA1.jpg"
/2 = "NA2.jpg"
/3 = "NA3.jpg"
/4 = "NA4.jpg"
/5 = "NA5.jpg"
</item>

<picture Alternative>
/items = Alternative
/select = noreplace
/position = (50, 50)
</picture>

<picture Alternative 2>
/items = Alternative
/select = current
/position = (50, 50)
</picture>

Thank you so much in advance!
Best regards,
rebsu

If I understand you correctly, you'll simply want to pair your "Suchbild" <picture> elements to your "Zielreiz" <picture>:

https://www.millisecond.com/support/docs/v4/html/howto/howtopairs.htm

This helps a lot, thank you Dave!
GO


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