# Generating a message/note for a random subset of surveys

Hi everyone,

I am trying to generate a note/message in Kobo which should only appear for a random subset of surveys. For example, we are visiting 10 households in a day, so this message should appear in 5 randomly selected surveys.

Is there a way Kobo can randomize the survey number and use it to autogenerate this note/message?

If someone has tried this before, please let me know!

Thanking in anticipation.

Hi
There is no direct way however the following steps can help.

1. Create a calculate question (Q1) using random function that generates a number between 1 and 2 using the formula below
once(int(2*random())+1)
2. You then create a note question (Q2) after the above random question.
3. You can then set a constraint in Q2 to appear when the random number Q1=1 hence only in some instances and not all the 10 visits will the note be displayed.

Regards
Stephane

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Hi Stephane,

Thank you for figuring this out! I have one question: if I want only two numbers, 0 and 1, to be randomly generated, will I be using this:

once(int(1*random())+0)

Please correct if this is wrong.

Thanks again.

Please note, your implied definition of ârandomâ above is, wellâŚ strictly not random. Well, at least not in terms of determining within each survey whether or not to show this ârandomâ question. As defined - âof 10 households visited, 5 should show the questionâ - would require randomly picking a subset of 5 of the 10 a priori, and somehow communicating this pre-selected list to the device when filling in the 10 (and no more or no less) surveys. Picking a random number of 0 or 1 within each form will, on average, show the question 50% of the time, but thereâs no guarantee that it will only show up on exactly 5 of the 10 surveys, or even show up on any of them at all!

Strictly speaking there is nothing (statistically) preventing exactly this from happening (without either a priori determining the 5 of 10, or somehow checking all previous instances - which then makes it no longer ârandomâ).

Hi
Responding on this

Yes that should give you a random selection of either 0 or 1.

Kindly note that as inferred by @Xiphware this does not mean that when your run this twice and you get say 0 the first time, then the second run will be a 1. So in other words regardless of your randomisation you may still end with less or more than 5 out of 10. However this is still random but does not guranttee you an exact selection of only 5 out of 10 choices.

Regards
Stephane

1 Like

Thanks guys, @stephanealoo and @Xiphware . I do understand that the randomness might not result in exactly 5 out of 10 surveys and the solution that has been shared above, this explains what I wanted.

Thanks again!

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