Randomization conditional on filter

Question

Dear all,

I would like to randomize a treatment and I want the random number to be drawn only for some of the respondents, i.e. conditional on them answering a given option (option 1 in my example).
I don't want the number to drawn if the respondent is answering any other option (2, 3, 4 and residual option in my case).

Based on https://www.soscisurvey.de/help/doku.php/en:create:randomization-per-block
I thought it would be enough to write the follwing code to achieve what I need

if (value('E001') == 1) {
// Randomize priming treatment
show('PR01');
put('PI01_01', value('PR01'));
}

However, when I do the preview, I can see that the number is drawn also if I select a different option from 1...
Note that this is a multiple choice question and it seems that this detail matters because when I select the single selection format, the draw works as I want (although then, when I select an option different from 1 I get that "The variable PI01_01 has not been asked on a previous page during this interview. Therefore value() cannot determine any answer, yet".) In either case I need the question to be multiple choice.

I would be greatful for any suggestion

Answer 1

Would you mind, posting your debug information for that page?

The most likely explanation is that you have places PR01 on the page via drag & drop. If that is the case, remove it, and leave only the show() to draw a number.

Note that this is a multiple choice question

Okay, then you're using the wrong variable. E001 will tell you how many options have been checked. I think your filter should be (value('E001_01') == 2).

Take a look in the variables listing to get more comfortable with the variables.

Comments

Thank you very much!

"I think your filter should be (value('E001_01') == 2)" solved the issue, the number is drawn only for option 1.

One further clarification:
I don't need the internal variable to record anything else, but since I get the warning message (below*) when a different option is selected, I wanted to double check if this could be problematic and if you recommend to do something about it


*The variable PI01_01 has not been asked on a previous page during this interview. Therefore value() cannot determine any answer, yet

---

If you do not need the put() line, you can simply remove it. That would be useful, if you wnated to store "something else" in the Variable, if the option 1 was not checked.

The error message sound like you have change the put() line as well, or are using a value('PI01_01') somewhere else in the questionnaire, and the put() line did not run, because the option 1 was not checked.