How to do this specific randomization? | XM Community
Question

How to do this specific randomization?

  • 21 November 2020
  • 2 replies
  • 1 view

Hello everyone!
I have a little problem and I would be very grateful if someone could help me. I want to make a study but I don't know how to make the design in Qualtrics. The design: I have 15 items. Each item has 5 conditions. I want to show the respondents each item but i want that each respondent could only see one condition of each item. So if someone sees item_1 in the third condition, the other conditions of this item can't be displayed to this respondent. So each respondent see all the 15 items but just in one condition. It would be random in which condition each item is displayed.
Plus, there are 5 conditions so I would like to show every respondent 3-3-3-3-3 of each conditions. The order of the display of the conditions would be random.
To summarize, each respondent would see all the 15 items. It is random in which condition each item is displayed. If one of the items is displayed, the respondent can't see this item again in none of the conditions. Moreover, each respondents see exactly 3 items of each conditions, the order of the conditions is random and it is also random which item is in which condition. Is it possible to make in Qualtrics?
I hope it is understandable. Thank you very much in advance.


2 replies

Userlevel 4
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It certainly is possible - with a bit of help from Javascript. I am sure there are many ways to do it without, but I find this to be simplest for me to implement.
First, create embedded data variables that hold as values the condition allocated for each item. Then, using javascript, we will allocated 1 condition per item such that the conditions are selected randomly for every item and one condition can only appear "number of items divided by possible conditions" times (in your case number of items = 15, possible conditions = 5, hence one condition can only appear 3 times). Lastly, we use block-level display logic to display the chosen condition for each item given the embedded data variables we created at the outset.
I've created a working version of this setup and attached it as .qsf. I've used 4 items and 2 possible conditions instead of 15 and 5, but it's relatively easy to expand (add embedded data variables in the same format and edit the top 2 lines of the JS to increase number of items and expand the possible conditions array; of course don't forget to add your new blocks and add display logic as I've done for the other ones).
How_to_do_this_specific_randomization.qsf
Hope this helps.

https://www.qualtrics.com/community/discussion/comment/32007#Comment_32007Hi there,
I am struggling with a similar problem (I have 12 items instead of 15 and 2 conditions instead of 5).
Unfortunately I can't open the file you attached. Is it possible to send the file as screenshot into this forum? That would be great!
Thanks!

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