I've got an experiment that I'm designing, and I've got the following issue. I'd like to present a video before a series of questions, but I'd like to choose from sets of videos to present. So, I've got four sets of four videos each, and I'd like to present one out of each set at random, and I'd like each of the set representatives to be presented in random order. Does that make sense?

Set 1 (a,b,c,d)
Set 2 (e,f,g,h)
Set 3 (i,j,k,l)
Set 4 (m,n,o,p)

The questionnaire should randomize sets 1-4, and when a set is presented, a single video is chosen at random from that set. So,

Set2 g
Set3 l
Set1 d
Set4 p

and

Set 3 k
Set 1 b
Set 4 o
Set 2 f

are both possible presentations.

Is this kind of randomization possible in MediaLab?