Millisecond Forums

I have no idea what page you are referring to with "registration page". If you mean the configuration page that asks you how group numbers should be generated, you simply select the URL query parameter option and then enter the query parameter's *name* in the respective field. The name is "gid" (without quotes).

Great, thanks, and this is what I should enter to the registration page, right? 
http://research.millisecond.com/username/experimentname.web?gid

No. It doesn't matter how you name the two <batch> elements, you do not need to name them at all. To be perfectly clear, the two <batch> elements need to exist in a *single* *.iqx file, not multiple. For the sake of example, create a file called 'batch.iqx' containing

<batch>
/ subjects = (1 of 2)
/ groupassignment = groupnumber
/ file = "a.iqx"
/ file = "b.iqx"
</batch>

<batch>
/ subjects = (2 of 2)
/ groupassignment = groupnumber
/ file = "c.iqx"
/ file = "d.iqx"
</batch>

The file called 'batch.iqx' is the one you register as your active web script. Which of the two <batch> elements contained in the file is administered, is determined by the group number that's passed in as discussed previously.

First batch would mean I have to name it <batch 1>? 

Yes, you can use the query parameter option to pass in the proper group directly. Suppose you call the query parameter gid, then

https://research.millisecond.com/yourusername/yourexperimentname.web?gid=1

will run the 1st <batch>, while

https://research.millisecond.com/yourusername/yourexperimentname.web?gid=2

will administer the 2nd <batch>.

Well, the groups are set to control and test group and I need the person from control group to be assigned to the batch for control group - lets say with the odd number. And the other way around. So, perhaps I only want to have one group with group ID: 1 and one group with group ID: 2. 

Is there a way to do this? 

> One more question - what do I have to choose while registering the script then?

This entirely depends on how you want to assign people to one of the two <batch> elements. The default is a random group number, which should be fine. Sequential should be fine as well (doesn't really make a difference here).

Great, just wanted to confirm.

One more question - what do I have to choose while registering the script then?
Choose how the group id should be determined: 

Thanks in advance! 

> Is it possible to put these two sets to one batch? for 2 different group assignments, I guess?

Yes, that's exactly correct. You can do

<batch>
/ subjects = (1 of 2)
/ groupassignment = groupnumber
/ file = "a.iqx"
/ file = "b.iqx"
</batch>

<batch>
/ subjects = (2 of 2)
/ groupassignment = groupnumber
/ file = "c.iqx"
/ file = "d.iqx"
</batch>

In the above example, participants with an *odd* group number would be administered a.iqx and b.iqx, while participants with an *even* group number would receive c.iqx and d.iqx.