andpru asked 7 years ago
Is there and easy way to randomize blocks?
This is, say I have
Block 1 = [1 2]
Block 2 = [1 3]
Block 3 = [1 4]
Is there are way that the blocks will be executed in a random order with each loading? I thought this used to exist at some point, the term superblock comes to mind ...
ap.
2 Answers
Duncan McLean Staff answered 7 years ago
Hi Andrew,
The "super block" idea has been on our feature list for a long time but it has not been implemented, so at the moment there is no way to do exactly what you are asking for. There are two main work-arounds I can think of:
- Design each trial to contain 2 trials internally. This option obviously falls apart pretty quickly if you need to have more than 2 trials in a block.
- Have multiple protocols with the blocks in different order and select a random protocol to run for a subject
apruszynski
replied 7 years ago Yes, I have implemented both those workarounds and they work fine. Just thought I remembered the superblock idea being already in a previous version. But I guess that’s faulty memory. I am not desperate for this feature.
Duncan McLean Staff answered 3 years ago
NOTE: The answer to this question seems to have been lost when we moved the website.
As of Dexterit-E 3.8 this is possible with a bit of extra copy and paste. As of Dexterit-E 3.8 it is possible to use brackets around items in a block list. The bracketing conveys the meaning of grouping TP's together. Section 6.11 of the Dexterit-E 3.8 User Guide has detailed examples.
The short answer for you is to set up a single block as: ([1, 2], [1,3], [1,4])
The numbers in [ ] will always be held together as a group and run in the exact order given. The surrounding ( ) that means that the order of the blocks inside will be randomized.
Duncan
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