counterbalancing 4 blocks

Comments

• may69

  May 2018

  Also, how can the results file comes out with a clear structure, for example, with block names?
• sebastiaan

  May 2018

  Hi,

  For this, you need to do a few things:

  • First get all possible orders of the four blocks. You can do this with itertools.permutations().
  • Then get one order (from all possible orders) based on the subject_nr variable
  • Use this order to define four variables: block1, block2, etc.
  • And then use these variables to determine which block is executed first, second, etc.

  This probably sounds a bit abstract, but it's not that complicated. I attached a simple example.

  Cheers!
  Sebastiaan

  
  
  Check out SigmundAI.eu for our OpenSesame AI assistant!
  
• ivan866

  April 2020 edited April 2020

  Is psychopy.tools.itertools deprecated? In favour of what?

  If so, why is it not MOVED to removed folder, like `iohub`'s deprecated modules?
• VictorVarela

  December 2020

  @sebastiaan Can you please attach the example you said you would attach???
• SezerReng

  January 2022

  Hi @sebastiaan

  I need your example too. Can please attach it if you still have it?

  Thanks a lot!
• sebastiaan

  January 2022

  Hi @SezerReng and @VictorVarela ,

  Here is the example again. (Some attachments got lost during a server crash some time ago.)

  counterbalancing.osexp

  The crucial part is the script in init_counterbalancing item. This gets the block order based on a permutation of all possible block orders and the subject number.

  import itertools as it
  
  # Gets a list of block orders, where each block order is itself a list
  # of the four block numbers, e.g. [3, 2, 1, 4]
  all_block_orders = list(it.permutations([1, 2, 3, 4]))
  # The current block order depends on the subject number, while wrapping
  # around so that participant 0 and 24 have the same order
  current_block_order = all_block_orders[var.subject_nr % len(all_block_orders)]
  print('block_order = {!s}'.format(current_block_order))
  # Assign the block orders to these variables, which will be used in the
  # loop table of counterbalanced_loop
  var.block1, var.block2, var.block3, var.block4 = current_block_order
  

  Good luck!

  — Sebastiaan

  
  
  Check out SigmundAI.eu for our OpenSesame AI assistant!
  
• SezerReng

  January 2022

  Sorry for the late reply Sebastiaan,

  It worked really smoothly, thank you so much for your solution!

  Best regards,

  Sezer