how to randomly asign participants to see 1 picture

Question

Hi,

I have 3 vignettes mails in form of a picture.
Participants shall be randomly assigned to 3 treatment groups. Thus, each participant only gets to see 1 of the vignettes.

How can I do this?

For now, I created a page with the pretext and added the three different pics. What are the next steps?

Thank you so much for advice, you'll save my thesis!

PS: Deutsch oder English, beides ist fine ;)

Answer 1

There's a quite elaborate manual on this: Randomization

This shoul explain the basics. If there are detail questions, don't hesitate to ask them :)