Hi,
I am currently setting up an experimental survey using LimeSurvey and I intend to implement a randomisation feature. The goal is to show one specific video to one group of participants, and a different video to another group, both group will answer the questionnaire. Could you provide guidance on how best to achieve this? Any tips or resources you could recommend would be greatly appreciated.Thank you for your assistance.

Hi,
at first I wonder why you didn't answer the questions about your version, your hosting, etc.
Not only that you ignored them, you removed them.

Now, the buzzword is : random number.

So you have to create a question of type "equation" (let's call it rn) where you create this random number.
Here you find the functions you can use
[url] www.limesurvey.org/manual/ExpressionScri...mplemented_functions [/url]
You see there is the function "rand(x,y)"

We extend this a bit to 
{if(is_empty(rn),rand(1,2),rn)}
Meaning: IF the random number is still empty, create one from 1-2, ELSE  keep it as it is.
This avoids, that a new random number is created if the respondent goes back to this question group.

Now your variable rn has one of the two possible values ("1" or "2")

You only have to set the condition of your two video questions respectively
One is displayed if rn==1
the other is displayed if rn==2

Please, read the manual about question types, about ExpressionScript.

Joffm