Constrain Loop Randomization in OSWeb

Comments

• sebastiaan

  June 2020 edited June 2020

  Hi Angelina,

  The only way I can think of is to use an inline_javascript ithat uses a counter (repetition ) to keep track of how often a particular value is repeated for, in the example, the variable condition . And then you can use a run-if statement to skip all items in the trial sequence when repetition exceeds a certain value. Conversely, a repeat_cycle is run only when it exceeds this value.

  It's not very elegant, but it should do the trick in most scenarios!

  Cheers,

  Sebastiaan

  if ((typeof(vars.previous_condition) !== 'undefined') && (vars.previous_condition === vars.condition)) {
      vars.repetition += 1
  } else {
      vars.repetition = 0
  }
  console.log('previous: ' + vars.previous_condition + ' current: ' + vars.condition + ' repetition: ' + vars.repetition)
  vars.previous_condition = vars.condition
  

  

  

  constrain.osexp

  
  

  
  
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• Angelina16

  June 2020

  Thank you so much Sebastian! This soulution works perfectly for my experiment!!
• Yuyanxue

  June 2020

  Hi Sebastiaan,

  I have tried this inline_javascript that you suggested to Angelina with the offline version of Opensesame, but it did not work (No module named inline_javascript). I assume this javascript only works for OSWeb. Is there similar code that can be used for inline_Pythonscript?

  I found this discussion from 2013 (https://forum.cogsci.nl/index.php?p=/discussion/310/solved-pseudorandom-with-lexical-decision) and step 8 here (https://kvonholzen.github.io/Tutorials_Open_Sesame_Lexical_decision.html#step_8:_pseudorandomize_the_order_of_trials). But these two solutions do not look as straightforward as the one for OSWeb.

  
  

  I am attaching my unfinished experiment. For example, in subblock 1.1, I would like to pseudo-randomize the trails to keep sequences of expected ‘yes’ (or 'no') responses to no more than three in a row. Is there an essay way to implement this?

  Thank you so much in advance!

  Best regards,

  Mengzhu

  Visual_LDT_try.osexp

  
  
• sebastiaan

  June 2020

  Hi Mengzhu,

  The solution described in this post is for OSWeb (the online runtime of OpenSesame), which doesn't support OpenSesame's normal pseudorandomization functionality. That makes it a bit complex.

  But if you want to run your experiment on the desktop, you can make use of loop constraints, which is much easier.

  For example, in subblock 1.1, I would like to pseudo-randomize the trails to keep sequences of expected ‘yes’ (or 'no') responses to no more than three in a row.

  Let's say that you have a variable expected_response , then you could add the following constraint to the end of the loop script:

  constrain expected_response maxrep=3
  

  See also:

  • https://osdoc.cogsci.nl/3.3/manual/structure/loop/#pseudorandomization

  Hope this helps!

  Cheers,

  Sebastiaan

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

  June 2020

  Thank you. It worked perfectly!