Randomize 2 variables with several levels

Comments

• sebastiaan

  October 9

  Hi @Naïde ,

  Since you have only ten numbers (and twelve words per emotion), I assume that you want to randomly sample from these numbers with replacement. If so, then it's actually quite easy, because you can simply create a loop table with three columns: word , emotion ('positive', 'negative', or 'neutral'), and value ('high' or 'low'). Then at the start of the trial sequence, you insert an inline_script with a short piece of code in the prepare phase to actually set the number variable, like so:

  import random
  if value == 'low':
      number = random.randint(1, 5)
  else:
      number = random.randint(8, 12)
  

  Does that make sense?

  — Sebastiaan

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

  October 9

  Hi @sebastiaan

  Thank you very much for your help. The code works perfectly to randomly assign a number. The problem is that I also want to randomize the high / low value for the words. For instance I want the first positive word to be either low or high value across participants.

  I tried to creat one loop table with 3 columns corresponding to the 3 emotional conditions (positive / negative / neutral), and then a sub loop table with a full factorial design leading to 6 conditions (positive-high, positive-low, neutral-high, neutral-low, negative-high, negative-low).

  Before these loops I placed the following inline_script to define the value (high/low) and randomize the numbers

  import random

  low=random.randint(0,5)

  high=random.randint(8,12)

  
  

  

  

  Now I would like to

  1/ randomly assign a value high or low to each word

  2/ counterbalance the proportion of high / low value words within each emotional condition (e.g. 50% of positive word with high value and 50% with low value)

  I tried to import pseudorandom tu use the constrain function but it doesn't work. Opensesame indicates that pseudorandom is imported but not used.

  I am sorry for these basic questions, I am a new user of opensesame and not familiar with Python (it took me a while to figure out how I could import the random plugin...)

  
  

  Again, thanks a lot for your answer and your help :)
• eduard

  October 9

  Hi,

  See attached experiment for a demo how you can accomplish this with Python coding.

  Newexperiment.osexp

  Essentially I create the stimuli once per block, and then access them one by one in the trials. When doing that that I get 36 words, 12 in each valence condition and of these 12, 6 with a high number and 6 with a low one. That's what you want, right?

  Eduard

  
• Naïde

  October 11

  Hi @eduard

  Your programm is wonderful, the randomization is perfect !!

  Thank you so much for your help ! 😀

  The only issue I have now is that among the 12 words of each valence condition, some are presented several times while some do not appear. Is there a way to tell the programm that once a word has been presented it must not be presented again in the following block ?

  Experience_V4.osexp

  
  
• Naïde

  October 11

  @eduard

  Finally it works perfectly for me, you saved me a lot of precious time !

  Thanks again !