Millisecond Forums » Millisecond Forums » Inquisit 6 » On Randomization

On Randomization

Apalapucia — Tue, 27 May 2025 12:35:24 GMT

Hey everyone!

I’m working on a study in Inquisit 6 where I need to present a set of images multiple times, and I am quite new at coding. My main goal is:

To show all images an equal number of times throughout the experiment.
To present the images in a random order each time, so the order isn’t predictable.
To keep the code as simple and minimal as possible.

I have 16 images and want each to appear 5 times total (80 trials). How can I set up the loop or list so it randomises the images every repetition, but still keeps the frequency equal? Any advice or example code snippets would be much appreciated!

Thanks in advance.

<item Black_Sad>
/1 = "B01_Sad_02_Melancholy.bmp"
/2 = "B02_Sad_02_Melancholy.bmp"
/3 = "B03_Sad_02_Melancholy.bmp"
/4 = "B04_Sad_02_Melancholy.bmp"
</item>

<item Black_Angry>
/1 = "B01_Anger_02_Indignation.bmp"
/2 = "B02_Anger_02_Indignation.bmp"
/3 = "B03_Anger_02_Indignation.bmp"
/4 = "B04_Anger_02_Indignation.bmp"
</item>

(...)

<picture Black_Sad_p>
/items = Black_Sad
/size = (50%, 50%)
/ select = noreplace
/ erase = true(0, 0, 0)
</picture>

<picture Black_Angry_p>
/items = Black_Angry
/size = (50%, 50%)
/ select = noreplace
/ erase = true(0, 0, 0)
</picture>

(...)

<block ExperimentalBlock1>
/ preinstructions = (test) // Instructions for the first experimental block
/ trials = [1-80 = noreplace (Black_Angry_l, Black_Sad_r, White_Angry_l, White_Sad_r)]
/ bgstim = (AngerLeft, SadnessRight)
</block>

<block ExperimentalBlock2>
/ preinstructions = (test2) // Instructions for the first experimental block
/ trials = [1-80 = noreplace (Black_Angry_r, Black_Sad_l, White_Angry_r, White_Sad_l)]
/ bgstim = (AngerRight, SadnessLeft)
</block>

RE: On Randomization

Dave — Tue, 27 May 2025 12:35:24 GMT

+x[quote]

[b]Apalapucia - 5/27/2025[/b]
+x[quote]

[b]Dave - 5/27/2025[/b]
+x[quote]

[b]Dave - 5/27/2025[/b]
+x[quote]

[b]Apalapucia - 5/27/2025[/b]
+x[quote]

[b]Dave - 5/27/2025[/b]
+x[quote]

[b]Apalapucia - 5/27/2025[/b]
Hey everyone!

I’m working on a study in Inquisit 6 where I need to present a set of images multiple times, and I am quite new at coding. My main goal is:

To show all images an equal number of times throughout the experiment.
To present the images in a random order each time, so the order isn’t predictable.
To keep the code as simple and minimal as possible.

I have 16 images and want each to appear 5 times total (80 trials). How can I set up the loop or list so it randomises the images every repetition, but still keeps the frequency equal? Any advice or example code snippets would be much appreciated!

Thanks in advance.

<item Black_Sad>
/1 = "B01_Sad_02_Melancholy.bmp"
/2 = "B02_Sad_02_Melancholy.bmp"
/3 = "B03_Sad_02_Melancholy.bmp"
/4 = "B04_Sad_02_Melancholy.bmp"
</item>

<item Black_Angry>
/1 = "B01_Anger_02_Indignation.bmp"
/2 = "B02_Anger_02_Indignation.bmp"
/3 = "B03_Anger_02_Indignation.bmp"
/4 = "B04_Anger_02_Indignation.bmp"
</item>

(...)

<picture Black_Sad_p>
/items = Black_Sad
/size = (50%, 50%)
/ select = noreplace
/ erase = true(0, 0, 0)
</picture>

<picture Black_Angry_p>
/items = Black_Angry
/size = (50%, 50%)
/ select = noreplace
/ erase = true(0, 0, 0)
</picture>

(...)

<block ExperimentalBlock1>
/ preinstructions = (test) // Instructions for the first experimental block
/ trials = [1-80 = noreplace (Black_Angry_l, Black_Sad_r, White_Angry_l, White_Sad_r)]
/ bgstim = (AngerLeft, SadnessRight)
</block>

<block ExperimentalBlock2>
/ preinstructions = (test2) // Instructions for the first experimental block
/ trials = [1-80 = noreplace (Black_Angry_r, Black_Sad_l, White_Angry_r, White_Sad_l)]
/ bgstim = (AngerRight, SadnessLeft)
</block>

[/quote]

The code snippet is not useful for answerring your question without the <trial> elements that actually display the <picture> stimuli as well as a better descriptiion of what you actually want.
[/quote]

<trial Black_Angry_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Angry_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial Black_Sad_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Sad_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial Black_Angry_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Angry_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial Black_Sad_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Sad_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

************************************** Trials White**************************************************

<trial White_Sad_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Sad_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial White_Angry_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Angry_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial White_Sad_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Sad_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial White_Angry_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Angry_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

Hey, these are the trial snippets!
[/quote]

You'll want separate <picture> elements per trial. You don't want trials Black_Angry_l and Black_Angry_r to sample from the same, single picture element Black_Angry_p if you want to end up with each of the 4 items presented the same amount of times in the Black_Angry_l and Black_Angry_r context,
[/quote]

See e.g. https://forums.millisecond.com/Topic17764.aspx for an explanation of how the sampling works.
[/quote]

Thank you so much! I will check this out.
[/quote]

One other thing, which may or may not be relevant for your current study (it's not clear from your description):

This

[code] / trials = [1-80 = noreplace (Black_Angry_l, Black_Sad_r, White_Angry_l, White_Sad_r)] [/code]

creates a single pool containing 20 Black_Angry_l, 20 Black_Sad_r, 20 White_Angry_l, and 20 White_Sad_r trials. These will be sampled in random order.

If, instead, you want to have chunks of 16 trials (4 x Black_Angry_l, 4 x Black_Sad_r, 4 x White_Angry_l, 4 x White_Sad_r) repeated 5 times, then that would be:

[code]/ trials = [
    1-16 = noreplace(Black_Angry_l, Black_Sad_r, White_Angry_l, White_Sad_r);
    17-32 = noreplace(Black_Angry_l, Black_Sad_r, White_Angry_l, White_Sad_r);
    33-48 = noreplace(Black_Angry_l, Black_Sad_r, White_Angry_l, White_Sad_r);
    49-64 = noreplace(Black_Angry_l, Black_Sad_r, White_Angry_l, White_Sad_r);
    65-80 = noreplace(Black_Angry_l, Black_Sad_r, White_Angry_l, White_Sad_r);
][/code]

RE: On Randomization

Apalapucia — Tue, 27 May 2025 12:19:03 GMT

+x[quote]

[b]Dave - 5/27/2025[/b]
+x[quote]

[b]Dave - 5/27/2025[/b]
+x[quote]

[b]Apalapucia - 5/27/2025[/b]
+x[quote]

[b]Dave - 5/27/2025[/b]
+x[quote]

[b]Apalapucia - 5/27/2025[/b]
Hey everyone!

I’m working on a study in Inquisit 6 where I need to present a set of images multiple times, and I am quite new at coding. My main goal is:

To show all images an equal number of times throughout the experiment.
To present the images in a random order each time, so the order isn’t predictable.
To keep the code as simple and minimal as possible.

I have 16 images and want each to appear 5 times total (80 trials). How can I set up the loop or list so it randomises the images every repetition, but still keeps the frequency equal? Any advice or example code snippets would be much appreciated!

Thanks in advance.

<item Black_Sad>
/1 = "B01_Sad_02_Melancholy.bmp"
/2 = "B02_Sad_02_Melancholy.bmp"
/3 = "B03_Sad_02_Melancholy.bmp"
/4 = "B04_Sad_02_Melancholy.bmp"
</item>

<item Black_Angry>
/1 = "B01_Anger_02_Indignation.bmp"
/2 = "B02_Anger_02_Indignation.bmp"
/3 = "B03_Anger_02_Indignation.bmp"
/4 = "B04_Anger_02_Indignation.bmp"
</item>

(...)

<picture Black_Sad_p>
/items = Black_Sad
/size = (50%, 50%)
/ select = noreplace
/ erase = true(0, 0, 0)
</picture>

<picture Black_Angry_p>
/items = Black_Angry
/size = (50%, 50%)
/ select = noreplace
/ erase = true(0, 0, 0)
</picture>

(...)

<block ExperimentalBlock1>
/ preinstructions = (test) // Instructions for the first experimental block
/ trials = [1-80 = noreplace (Black_Angry_l, Black_Sad_r, White_Angry_l, White_Sad_r)]
/ bgstim = (AngerLeft, SadnessRight)
</block>

<block ExperimentalBlock2>
/ preinstructions = (test2) // Instructions for the first experimental block
/ trials = [1-80 = noreplace (Black_Angry_r, Black_Sad_l, White_Angry_r, White_Sad_l)]
/ bgstim = (AngerRight, SadnessLeft)
</block>

[/quote]

The code snippet is not useful for answerring your question without the <trial> elements that actually display the <picture> stimuli as well as a better descriptiion of what you actually want.
[/quote]

<trial Black_Angry_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Angry_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial Black_Sad_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Sad_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial Black_Angry_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Angry_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial Black_Sad_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Sad_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

************************************** Trials White**************************************************

<trial White_Sad_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Sad_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial White_Angry_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Angry_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial White_Sad_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Sad_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial White_Angry_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Angry_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

Hey, these are the trial snippets!
[/quote]

You'll want separate <picture> elements per trial. You don't want trials Black_Angry_l and Black_Angry_r to sample from the same, single picture element Black_Angry_p if you want to end up with each of the 4 items presented the same amount of times in the Black_Angry_l and Black_Angry_r context,
[/quote]

See e.g. https://forums.millisecond.com/Topic17764.aspx for an explanation of how the sampling works.
[/quote]

Thank you so much! I will check this out.

RE: On Randomization

Dave — Tue, 27 May 2025 12:16:20 GMT

+x[quote]

[b]Dave - 5/27/2025[/b]
+x[quote]

[b]Apalapucia - 5/27/2025[/b]
+x[quote]

[b]Dave - 5/27/2025[/b]
+x[quote]

[b]Apalapucia - 5/27/2025[/b]
Hey everyone!

I’m working on a study in Inquisit 6 where I need to present a set of images multiple times, and I am quite new at coding. My main goal is:

To show all images an equal number of times throughout the experiment.
To present the images in a random order each time, so the order isn’t predictable.
To keep the code as simple and minimal as possible.

I have 16 images and want each to appear 5 times total (80 trials). How can I set up the loop or list so it randomises the images every repetition, but still keeps the frequency equal? Any advice or example code snippets would be much appreciated!

Thanks in advance.

<item Black_Sad>
/1 = "B01_Sad_02_Melancholy.bmp"
/2 = "B02_Sad_02_Melancholy.bmp"
/3 = "B03_Sad_02_Melancholy.bmp"
/4 = "B04_Sad_02_Melancholy.bmp"
</item>

<item Black_Angry>
/1 = "B01_Anger_02_Indignation.bmp"
/2 = "B02_Anger_02_Indignation.bmp"
/3 = "B03_Anger_02_Indignation.bmp"
/4 = "B04_Anger_02_Indignation.bmp"
</item>

(...)

<picture Black_Sad_p>
/items = Black_Sad
/size = (50%, 50%)
/ select = noreplace
/ erase = true(0, 0, 0)
</picture>

<picture Black_Angry_p>
/items = Black_Angry
/size = (50%, 50%)
/ select = noreplace
/ erase = true(0, 0, 0)
</picture>

(...)

<block ExperimentalBlock1>
/ preinstructions = (test) // Instructions for the first experimental block
/ trials = [1-80 = noreplace (Black_Angry_l, Black_Sad_r, White_Angry_l, White_Sad_r)]
/ bgstim = (AngerLeft, SadnessRight)
</block>

<block ExperimentalBlock2>
/ preinstructions = (test2) // Instructions for the first experimental block
/ trials = [1-80 = noreplace (Black_Angry_r, Black_Sad_l, White_Angry_r, White_Sad_l)]
/ bgstim = (AngerRight, SadnessLeft)
</block>

[/quote]

The code snippet is not useful for answerring your question without the <trial> elements that actually display the <picture> stimuli as well as a better descriptiion of what you actually want.
[/quote]

<trial Black_Angry_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Angry_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial Black_Sad_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Sad_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial Black_Angry_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Angry_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial Black_Sad_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Sad_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

************************************** Trials White**************************************************

<trial White_Sad_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Sad_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial White_Angry_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Angry_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial White_Sad_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Sad_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial White_Angry_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Angry_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

Hey, these are the trial snippets!
[/quote]

You'll want separate <picture> elements per trial. You don't want trials Black_Angry_l and Black_Angry_r to sample from the same, single picture element Black_Angry_p if you want to end up with each of the 4 items presented the same amount of times in the Black_Angry_l and Black_Angry_r context,
[/quote]

See e.g. https://forums.millisecond.com/Topic17764.aspx for an explanation of how the sampling works.

RE: On Randomization

Dave — Tue, 27 May 2025 12:12:47 GMT

+x[quote]

[b]Apalapucia - 5/27/2025[/b]
+x[quote]

[b]Dave - 5/27/2025[/b]
+x[quote]

[b]Apalapucia - 5/27/2025[/b]
Hey everyone!

I’m working on a study in Inquisit 6 where I need to present a set of images multiple times, and I am quite new at coding. My main goal is:

To show all images an equal number of times throughout the experiment.
To present the images in a random order each time, so the order isn’t predictable.
To keep the code as simple and minimal as possible.

I have 16 images and want each to appear 5 times total (80 trials). How can I set up the loop or list so it randomises the images every repetition, but still keeps the frequency equal? Any advice or example code snippets would be much appreciated!

Thanks in advance.

<item Black_Sad>
/1 = "B01_Sad_02_Melancholy.bmp"
/2 = "B02_Sad_02_Melancholy.bmp"
/3 = "B03_Sad_02_Melancholy.bmp"
/4 = "B04_Sad_02_Melancholy.bmp"
</item>

<item Black_Angry>
/1 = "B01_Anger_02_Indignation.bmp"
/2 = "B02_Anger_02_Indignation.bmp"
/3 = "B03_Anger_02_Indignation.bmp"
/4 = "B04_Anger_02_Indignation.bmp"
</item>

(...)

<picture Black_Sad_p>
/items = Black_Sad
/size = (50%, 50%)
/ select = noreplace
/ erase = true(0, 0, 0)
</picture>

<picture Black_Angry_p>
/items = Black_Angry
/size = (50%, 50%)
/ select = noreplace
/ erase = true(0, 0, 0)
</picture>

(...)

<block ExperimentalBlock1>
/ preinstructions = (test) // Instructions for the first experimental block
/ trials = [1-80 = noreplace (Black_Angry_l, Black_Sad_r, White_Angry_l, White_Sad_r)]
/ bgstim = (AngerLeft, SadnessRight)
</block>

<block ExperimentalBlock2>
/ preinstructions = (test2) // Instructions for the first experimental block
/ trials = [1-80 = noreplace (Black_Angry_r, Black_Sad_l, White_Angry_r, White_Sad_l)]
/ bgstim = (AngerRight, SadnessLeft)
</block>

[/quote]

The code snippet is not useful for answerring your question without the <trial> elements that actually display the <picture> stimuli as well as a better descriptiion of what you actually want.
[/quote]

<trial Black_Angry_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Angry_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial Black_Sad_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Sad_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial Black_Angry_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Angry_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial Black_Sad_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Sad_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

************************************** Trials White**************************************************

<trial White_Sad_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Sad_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial White_Angry_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Angry_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial White_Sad_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Sad_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial White_Angry_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Angry_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

Hey, these are the trial snippets!
[/quote]

You'll want separate <picture> elements per trial. You don't want trials Black_Angry_l and Black_Angry_r to sample from the same, single picture element Black_Angry_p if you want to end up with each of the 4 items presented the same amount of times in the Black_Angry_l and Black_Angry_r context,

RE: On Randomization

Apalapucia — Tue, 27 May 2025 12:08:09 GMT

+x[quote]

[b]Dave - 5/27/2025[/b]
+x[quote]

[b]Apalapucia - 5/27/2025[/b]
Hey everyone!

I’m working on a study in Inquisit 6 where I need to present a set of images multiple times, and I am quite new at coding. My main goal is:

To show all images an equal number of times throughout the experiment.
To present the images in a random order each time, so the order isn’t predictable.
To keep the code as simple and minimal as possible.

I have 16 images and want each to appear 5 times total (80 trials). How can I set up the loop or list so it randomises the images every repetition, but still keeps the frequency equal? Any advice or example code snippets would be much appreciated!

Thanks in advance.

<item Black_Sad>
/1 = "B01_Sad_02_Melancholy.bmp"
/2 = "B02_Sad_02_Melancholy.bmp"
/3 = "B03_Sad_02_Melancholy.bmp"
/4 = "B04_Sad_02_Melancholy.bmp"
</item>

<item Black_Angry>
/1 = "B01_Anger_02_Indignation.bmp"
/2 = "B02_Anger_02_Indignation.bmp"
/3 = "B03_Anger_02_Indignation.bmp"
/4 = "B04_Anger_02_Indignation.bmp"
</item>

(...)

<picture Black_Sad_p>
/items = Black_Sad
/size = (50%, 50%)
/ select = noreplace
/ erase = true(0, 0, 0)
</picture>

<picture Black_Angry_p>
/items = Black_Angry
/size = (50%, 50%)
/ select = noreplace
/ erase = true(0, 0, 0)
</picture>

(...)

<block ExperimentalBlock1>
/ preinstructions = (test) // Instructions for the first experimental block
/ trials = [1-80 = noreplace (Black_Angry_l, Black_Sad_r, White_Angry_l, White_Sad_r)]
/ bgstim = (AngerLeft, SadnessRight)
</block>

<block ExperimentalBlock2>
/ preinstructions = (test2) // Instructions for the first experimental block
/ trials = [1-80 = noreplace (Black_Angry_r, Black_Sad_l, White_Angry_r, White_Sad_l)]
/ bgstim = (AngerRight, SadnessLeft)
</block>

[/quote]

The code snippet is not useful for answerring your question without the <trial> elements that actually display the <picture> stimuli as well as a better descriptiion of what you actually want.
[/quote]

<trial Black_Angry_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Angry_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial Black_Sad_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Sad_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial Black_Angry_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Angry_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial Black_Sad_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=Black_Sad_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

************************************** Trials White**************************************************

<trial White_Sad_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Sad_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial White_Angry_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Angry_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial White_Sad_l>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Sad_p; 500=blank]
/ correctresponse = ("a")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

<trial White_Angry_r>
/ pretrialpause = 400
/ stimulustimes=[0=fixation; 300=White_Angry_p; 500=blank]
/ correctresponse = ("l")
/ validresponse = ("a", "l")
/ errormessage = true(error,400)
</trial>

Hey, these are the trial snippets!

RE: On Randomization

Dave — Tue, 27 May 2025 12:00:39 GMT

+x[quote]

[b]Apalapucia - 5/27/2025[/b]
Hey everyone!

I’m working on a study in Inquisit 6 where I need to present a set of images multiple times, and I am quite new at coding. My main goal is:

To show all images an equal number of times throughout the experiment.
To present the images in a random order each time, so the order isn’t predictable.
To keep the code as simple and minimal as possible.

I have 16 images and want each to appear 5 times total (80 trials). How can I set up the loop or list so it randomises the images every repetition, but still keeps the frequency equal? Any advice or example code snippets would be much appreciated!

Thanks in advance.

<item Black_Sad>
/1 = "B01_Sad_02_Melancholy.bmp"
/2 = "B02_Sad_02_Melancholy.bmp"
/3 = "B03_Sad_02_Melancholy.bmp"
/4 = "B04_Sad_02_Melancholy.bmp"
</item>

<item Black_Angry>
/1 = "B01_Anger_02_Indignation.bmp"
/2 = "B02_Anger_02_Indignation.bmp"
/3 = "B03_Anger_02_Indignation.bmp"
/4 = "B04_Anger_02_Indignation.bmp"
</item>

(...)

<picture Black_Sad_p>
/items = Black_Sad
/size = (50%, 50%)
/ select = noreplace
/ erase = true(0, 0, 0)
</picture>

<picture Black_Angry_p>
/items = Black_Angry
/size = (50%, 50%)
/ select = noreplace
/ erase = true(0, 0, 0)
</picture>

(...)

<block ExperimentalBlock1>
/ preinstructions = (test) // Instructions for the first experimental block
/ trials = [1-80 = noreplace (Black_Angry_l, Black_Sad_r, White_Angry_l, White_Sad_r)]
/ bgstim = (AngerLeft, SadnessRight)
</block>

<block ExperimentalBlock2>
/ preinstructions = (test2) // Instructions for the first experimental block
/ trials = [1-80 = noreplace (Black_Angry_r, Black_Sad_l, White_Angry_r, White_Sad_l)]
/ bgstim = (AngerRight, SadnessLeft)
</block>

[/quote]

The code snippet is not useful for answerring your question without the <trial> elements that actually display the <picture> stimuli as well as a better descriptiion of what you actually want.