Display a variable according to a probability

[nohandoye]

HELLO. I survey households and in each household I interview several individuals. The individuals’ questions are in a repeated group. There are 2 note in the repeated group and I would like one note per household to appear at random. A note must appear at random according to the following probabilities. Note 1 with proba 0.6 and Note 2 with proba 0.3
There is one note per household and the note does not change for the individuals in the household. Thank you for helping me

[nohandoye]

Hello Bro,

Can you help me please.
i just sent a message in a forum.
Thanks you

[Kal_Lam]

@nohandoye, maybe this post discussed previously should be helpful for you:

Help with Randomizing Question Blocks in XLSForm

There are a few different ways you can do this, perhaps the simplest being to group all your blocks (ie subgroups!) into a group, generate all possible permutations [for randomizing 3 things will give you a total of 6 possible permutations] and then just generating a random number between 1 and 6 and using that in a relevant expression against each permutation super-group. This is basically the same brute-approach taken to randomizing questions: create a group for all possible permutations, and…

[nohandoye]

Thanks you @Kal_Lam
But have you another example for randomizing questions (not block)?
Thanks

[Xiphware]

@nohandoye

A note must appear at random according to the following probabilities. Note 1 with proba 0.6 and Note 2 with proba 0.3

Try something like this:

SimpleForm.xlsx (14.6 KB)

This can go wherever you like, inside a repeat group or not as desired. The important thing is to generate a fixed random number once() - so it doesn’t keep changing - and for the relevant check for each note to test mutually exclusive ranges.

There is one note per household

I observe that, given your prescribed probabilities above, this means 10% of the time a note wont be shown. And that you only show one note of the other [if this is not in fact the case, and both notes can sometimes appear together, then just simplify the relevant check accordingly so they are not mutually exclusive].

[nohandoye]

Thank you very much @Xiphware . But what can I add to the formula to have a proba that does not change between individuals belonging to the household and a proba that changes only by household?

[Xiphware]

If you have a repeat iteration for each household, then the ${rnd} calculation goes inside that repeat.

[nohandoye]

the repeat iteration is only for each household’s member (not for household).

[nohandoye]

@Xiphware Thanks you very much