[solved] randomizing a sequence of four blocks

Comments

• sebastiaan

  May 2012 edited July 2013

  Hi Andrea,

  Right, if you set a loop to random, it will only randomize the order of the loop. The order of the items in a sequence is always fixed. Still, you can mimic a random sequence quite easily with a simple inline_script. See below, some instructions are added as code comments.

  Cheers!
  Sebastiaan

  from random import shuffle
  
  # Uncomment for 0.25 and before
  # exp = self.experiment
  
  # Create a list of items that are part of the sequence
  # These items must be present somewhere in the experiment.
  # An easy solution is to add them to a dummy_sequence at
  # the start of the trial and set the 'run if' statement of
  # the dummy_sequence to 'never'.
  item_list = ['item1', 'item2', 'item3', 'item4']
  
  # Randomize the item order. Of course you can also do more
  # complicated things, such as have the order depend on the
  # subject nr, etc.
  shuffle(item_list)
  
  # First, prepare all items
  for item in item_list:
      exp.items[item].prepare()
  
  # Now run them!
  for item in item_list:
      exp.items[item].run()
  

  
  
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• embodiment

  May 2012 edited 10:57AM

  I have tried it just now and it works like a charm. You are the Genie of the Lamp.

  Thank you very much, Sebastian.
• gmz

  June 2016 edited 10:57AM

  Hi,
  I am brand new in Open Sesame and I know nothing about Python (I have been using SuperLab before). I have been trying to what Sebastiaan suggests, but I am not getting results. Could somebody explain it to me like "Open Sesame for dummies"?
  I need to run several blocks of 36 sequences (1 fix point+1 sentence+ 1 question about the previous sentence) in a random way (the presentation of the 36 pairs of sentence+question must be random), and collect RTs and yes/no answers.
  I understand the structure is pretty much like the one Andrea has, but with more sequences.
  And another thing: I am having problems with the excel with the collected data. It seems to be all mixed up and RTs are not recorded (or so it seems)...and I don´t know how to solve it.

  Thanks!
  Gabi
• aljaberi

  April 2018

  Hi dear
  please I,m looking for your help
  i have 10 universities i want to do the randomization to allocate it for intervention group and control group and i want to use the block methode who can i do it please
• L_Geissert

  June 2020

  Hey Sebastian,

  It tried to use the code you provided above. However, I don't understand this part:

  # Create a list of items that are part of the sequence
  # These items must be present somewhere in the experiment.
  # An easy solution is to add them to a dummy_sequence at
  # the start of the trial and set the 'run if' statement of
  # the dummy_sequence to 'never'.
  item_list = ['item1', 'item2', 'item3', 'item4']
  

  My experiment looks like that:

  

  And my goal is to randomize available_unavailable_mother, lovable_unlovable_self, and avialable_unavialble_father.

  
  

  Thank you in advance.

  Best, Laura
• sebastiaan

  June 2020

  Hi @L_Geissert ,

  You could put the three sequence s inside another containerloop - sequence structure. Then, in the container loop , you create a variable that determines which of the three sequence s is executed. And in the container sequence you use a run-if statement to determine which of that (sub) sequence is executed. Does that make sense?

  In the example below I used sketchpad s. In your case, you would replace these by the three sequence s that you want to randomize.

  

  random-order.osexp

  Cheers!

  Sebastiaan

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

  June 2020

  Hey Sebastiaan,

  it makes sense, thank you so much!

  Best,

  Laura