Millisecond Forums

Randomly allocating participants to conditions

https://forums.millisecond.com/Topic30155.aspx

By fm323 - 11/14/2020

Hi Dave,

Is it possible for participants to complete a Qualtrics questionnaire and then after clicking a link, be randomly directed and allocated to one of three Inquisit experiments? (They only do one of the experiments) I have three separate scripts - they're attached. How would I go about doing this? Let me know if there's anything more I need to provide. Thanks!
By Dave - 11/15/2020

fm323 - 11/14/2020
Hi Dave,

Is it possible for participants to complete a Qualtrics questionnaire and then after clicking a link, be randomly directed and allocated to one of three Inquisit experiments? (They only do one of the experiments) I have three separate scripts - they're attached. How would I go about doing this? Let me know if there's anything more I need to provide. Thanks!

Yes, you need to create a <batch> script, with three conditions (one per script), and that needs to be set as your online study's start script.

<batch>
/ groups = (1 of 3)
/ file = "kitten test.iqx"
</batch>

<batch>
/ groups = (2 of 3)
/ file = " horror.iqx"
</batch>

<batch>
/ groups = (3 of 3)
/ file = "neutral code.iqx"
</batch>

In your online experiments settings, select random group ID generation (without replacement) and indicate the number of groups as 3.
By fm323 - 11/16/2020

Dave - 11/15/2020
fm323 - 11/14/2020
Hi Dave,

Is it possible for participants to complete a Qualtrics questionnaire and then after clicking a link, be randomly directed and allocated to one of three Inquisit experiments? (They only do one of the experiments) I have three separate scripts - they're attached. How would I go about doing this? Let me know if there's anything more I need to provide. Thanks!

Yes, you need to create a <batch> script, with three conditions (one per script), and that needs to be set as your online study's start script.

<batch>
/ groups = (1 of 3)
/ file = "kitten test.iqx"
</batch>

<batch>
/ groups = (2 of 3)
/ file = " horror.iqx"
</batch>

<batch>
/ groups = (3 of 3)
/ file = "neutral code.iqx"
</batch>

In your online experiments settings, select random group ID generation (without replacement) and indicate the number of groups as 3.

Sorry to be a pain, but is this the same in Inquisit 5? So far I've been able to change my code to fit into Inquisit 5 (thanks!), but after I run the experiment it says "Setting has invalid text '/ groups = (1 of 3) '". It also says it for the other two groups. What do I change?
By Dave - 11/16/2020

fm323 - 11/16/2020
Dave - 11/15/2020
fm323 - 11/14/2020
Hi Dave,

Is it possible for participants to complete a Qualtrics questionnaire and then after clicking a link, be randomly directed and allocated to one of three Inquisit experiments? (They only do one of the experiments) I have three separate scripts - they're attached. How would I go about doing this? Let me know if there's anything more I need to provide. Thanks!

Yes, you need to create a <batch> script, with three conditions (one per script), and that needs to be set as your online study's start script.

<batch>
/ groups = (1 of 3)
/ file = "kitten test.iqx"
</batch>

<batch>
/ groups = (2 of 3)
/ file = " horror.iqx"
</batch>

<batch>
/ groups = (3 of 3)
/ file = "neutral code.iqx"
</batch>

In your online experiments settings, select random group ID generation (without replacement) and indicate the number of groups as 3.

Sorry to be a pain, but is this the same in Inquisit 5? So far I've been able to change my code to fit into Inquisit 5 (thanks!), but after I run the experiment it says "Setting has invalid text '/ groups = (1 of 3) '". It also says it for the other two groups. What do I change?

The equivalent in Inquisit 5 is

<batch>
/ subjects = (1 of 3)
/ groupassignment = groupnumber
/ file = "kitten test.iqx"
</batch>

<batch>
/ subjects = (2 of 3)
/ groupassignment = groupnumber
/ file = " horror.iqx"
</batch>

<batch>
/ subjects = (3 of 3)
/ groupassignment = groupnumber
/ file = "neutral code.iqx"
</batch>
By dillonk - 11/23/2020

Hi all, 

I have a question related to this topic. In my experiment, I set up two groups to include or exclude an additional task in the script. I set up the group ids so that they are determined by URL, as our groups depend on whether or not the participant is completing an optional MRI. In the experiment, I am including the Emotional Stroop. I need to set up the stroop so that the groups will randomly starts with neutral words or aggression words. Is there a way to add this randomization component into the stroop while maintaining group ids being determined by URL?

Thanks in advance!
By Dave - 11/23/2020

dillonk - 11/24/2020
Hi all, 

I have a question related to this topic. In my experiment, I set up two groups to include or exclude an additional task in the script. I set up the group ids so that they are determined by URL, as our groups depend on whether or not the participant is completing an optional MRI. In the experiment, I am including the Emotional Stroop. I need to set up the stroop so that the groups will randomly starts with neutral words or aggression words. Is there a way to add this randomization component into the stroop while maintaining group ids being determined by URL?

Thanks in advance!

You can assign any between-subjects manipulation you set up in the stroop script randomly per /groupassignment = random.. That, then, would not rely on group ids.
By dillonk - 11/23/2020

Thanks