Random-once() randomization algorithm

I'm curious if anyone can explain what the underlying randomization algorithm is for SurveyCTO's random-once() function?

We plan to randomly select respondents to respond to 3 different hypothetical scenarios in a survey. We don't want any discernible patterns to emerge in which scenario a respondent will be assigned to. Thanks!

Nathan Cutler
Impact Evaluation Program Associate, Social Impact Inc.

Hi Nate,

SurveyCTO calls the same Java random-number generator as the core ODK
random() function, which in turn calls this Java function to generate
random numbers between 0 and 1:

http://docs.oracle.com/javase/6/docs/api/java/util/Random.html#nextDouble()

That page references one textbook, and you can probably find other articles
on Java's random-number capabilities.

You should be in good hands, but of course with small numbers of
observations you can always see patterns in random numbers.

Best,

Chris

ยทยทยท On Fri, Feb 21, 2014 at 11:44 AM, Nathan Cutler wrote:

I'm curious if anyone can explain what the underlying randomization
algorithm is for SurveyCTO's random-once() function?

We plan to randomly select respondents to respond to 3 different
hypothetical scenarios in a survey. We don't want any discernible patterns
to emerge in which scenario a respondent will be assigned to. Thanks!

Nathan Cutler
Impact Evaluation Program Associate, Social Impact Inc.

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Thanks a lot Chris! I figured we were in good hands and just wanted to verify on behalf of my PI. Much appreciated and I hope things are well with you.

Nate