Millisecond Forums

There is no _difference_ between the two. /subjects and /groupassignment (always) work together.

Stating

<batch>
/ subjects = (1 of 2)
...
</batch>

is the same as stating

<batch>
/ subjects = (1 of 2)
/ groupassignment = subjectnumber
...
</batch>

In other words: Condition assignment by subject number is the default behavior; it's what Inqusit does if you don't explicitly tell it to behave differently. You do the latter by specifying a different groupassignment mode:

<batch>
/ subjects = (1 of 2)
/ groupassignment = groupnumber
...
</batch>

will perform condition assignment based on the numerical group id instead of using the subject id. For details on how condition assignment works, see https://www.millisecond.com/forums/Topic13856.aspx

Hope this helps.

Probably a stupid question, but why do I need /subjects and /groupassignment to randomize? So what is the difference between this two? 

Adding a couple of thoughts to the above:

#1: There is a risk I'm misunderstanding what exactly you mean by "[...] I refreshed the search bar in the same tab [...]". Could you elaborate? I.e., does it mean you move the cursor into the search / address bar and press enter, or that you clicked the refresh button in the bar, or something else?

#2: Chrome sometimes has weird caching behavior; if a "soft refresh" via the refresh button or by pressing F5 doesn't work, you can force a "hard refresh" via CTRL+F5.

Let me know what you find.

This very much sounds like an issue with Chrome for some reason not refreshing the page even if instructed to do so ("[...] I refreshed the search bar in the same tab [...]"). I don't know why that is and I'm not seeing this in my Chrome installation; refreshing seems to work as expected. So I have no idea here, I'm afraid. Are you seeing this on one particular machine only or across multiple computers?

Thank you for all of your help! I have one last issue that arose after implementing the sequential query. The experiment only runs on Google Chrome when a new Chrome session is established - i.e. I have to close Chrome and open a new session to begin the experiment, or else it goes straight to the "thank you" page as before. In both Safari and Firefox, the link worked when a I began a new web session, did not work when I refreshed the search bar in the same tab, but did worked when the link was copy-pasted into a new tab on the same session. Is there anything I can do to fix this issue? 

You can opt for generating group ids sequentially. There is no need to only repeat the exact numbers 1,2 and 3, because assignment is based on the modulus of the provided group number. I.e.

1 mod 3 = 1 -> condition 1
2 mod 3 = 2 -> condition 2
3 mod 3 = 0 -> condition 3
4 mod 3 = 1 -> condition 1
5 mod 3 = 2 -> condition 2
6 mod 3 = 0 -> condition 3
and so forth.

For details see this post: https://www.millisecond.com/forums/Topic13856.aspx

Is there a way to assign the group numbers 1, 2 and 3 on Inquisit Web and have it repeat this assignment (1, 2 and 3) for several hundred participants? 

This indicates an issue in your script(s). Specifically, you are passing in a group number or subject number for which no condition is assigned (and hence nothing will be run). You *will* see this happening in Inquisit Lab also, you just need to test out all the conditions (i.e., enter different group and/or subject numbers).

Hi Dave, 

Thank you for your quick reply. This fixed my randomization issue, but after several runs, the experiment began ending prematurely, presenting the "The session is complete, and your data were successfully uploaded. Thank you for your participation!" screen before the task even started. It seems like now the website might not be calling the scripts in my batch file, though it was working before online and continues to work on the desktop version of Inquisit. Any thoughts on this? 

Thank you so much!

Jess

I assume you are running this via Inquisit Web and that you've set your launch page up to generate random group numbers.. If so, you need to refresh the launch page between your test runs. The group number is generated when your browser first loads the page. If you don't refresh it, no new group number will be generated and you will get the same condition repeatedly.