Millisecond Forums

You'll have to do something along these lines:

// all will get this
<batch 1>
/ file = "OSP Project Visual Pack-PRACTICE.iqx"
</batch>

// then random assignment to one of the three pairs
// order within the pair is random
<batch 2>
/ subjects = (1 of 3)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-A.iqx"
/ file = "OSP Project Visual Pack-B.iqx"
</batch>

<batch 3>
/ subjects = (2 of 3)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-C.iqx"
/ file = "OSP Project Visual Pack-D.iqx"
</batch>

<batch 4>
/ subjects = (3 of 3)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-E.iqx"
/ file = "OSP Project Visual Pack-F.iqx"
</batch>

Thanks a lot for you response ! 
It's almost that. In fact, I would like this randomization of these pairs, but I want that one subject view all the pairs during the test. 
What I have to change for this?

Thanks to you, 
Chloé

Then the only option is to create <batch> conditions for all possible orders and then randomly assign to one of the orders. I.e.

// all will get this
<batch 1>
/ file = "OSP Project Visual Pack-PRACTICE.iqx"
</batch>

// condition 1: AB -> CD -> EF
// order within the pair is random
<batch 21>
/ subjects = (1 of 6)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-A.iqx"
/ file = "OSP Project Visual Pack-B.iqx"
</batch>

<batch 22>
/ subjects = (1 of 6)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-C.iqx"
/ file = "OSP Project Visual Pack-D.iqx"
</batch>

<batch 23>
/ subjects = (1 of 6)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-E.iqx"
/ file = "OSP Project Visual Pack-F.iqx"
</batch>

// condition 2: AB -> EF -> CD
// order within the pair is random
<batch 31>
/ subjects = (2 of 6)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-A.iqx"
/ file = "OSP Project Visual Pack-B.iqx"
</batch>

<batch 32>
/ subjects = (2 of 6)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-E.iqx"
/ file = "OSP Project Visual Pack-F.iqx"
</batch>

<batch 33>
/ subjects = (2 of 6)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-C.iqx"
/ file = "OSP Project Visual Pack-D.iqx"
</batch>

// condition 3: CD -> AB -> EF
// order within the pair is random
<batch 41>
/ subjects = (3 of 6)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-C.iqx"
/ file = "OSP Project Visual Pack-D.iqx"
</batch>

<batch 42>
/ subjects = (3 of 6)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-A.iqx"
/ file = "OSP Project Visual Pack-B.iqx"
</batch>

<batch 43>
/ subjects = (3 of 6)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-E.iqx"
/ file = "OSP Project Visual Pack-F.iqx"
</batch>

// condition 4: CD -> EF -> AB
// order within the pair is random
<batch 51>
/ subjects = (4 of 6)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-C.iqx"
/ file = "OSP Project Visual Pack-D.iqx"
</batch>

<batch 52>
/ subjects = (4 of 6)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-E.iqx"
/ file = "OSP Project Visual Pack-F.iqx"
</batch>

<batch 53>
/ subjects = (4 of 6)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-A.iqx"
/ file = "OSP Project Visual Pack-B.iqx"
</batch>

// condition 5: EF -> AB -> CD
// order within the pair is random
<batch 61>
/ subjects = (5 of 6)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-E.iqx"
/ file = "OSP Project Visual Pack-F.iqx"
</batch>

<batch 62>
/ subjects = (5 of 6)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-A.iqx"
/ file = "OSP Project Visual Pack-B.iqx"
</batch>

<batch 63>
/ subjects = (5 of 6)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-C.iqx"
/ file = "OSP Project Visual Pack-D.iqx"
</batch>

// condition 6: EF -> CD -> AB
// order within the pair is random
<batch 71>
/ subjects = (6 of 6)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-E.iqx"
/ file = "OSP Project Visual Pack-F.iqx"
</batch>

<batch 72>
/ subjects = (6 of 6)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-C.iqx"
/ file = "OSP Project Visual Pack-D.iqx"
</batch>

<batch 73>
/ subjects = (6 of 6)
/ groupassignment = random
/ selectionmode = random
/ file = "OSP Project Visual Pack-A.iqx"
/ file = "OSP Project Visual Pack-B.iqx"
</batch>

Thanks a lot !