[open] Counterbalancing

Comments

• eduard

  January 2015 edited 3:01PM

  Hi,

  You can do this with the variable wizard. If your 6 conditions result from crossing 2 factors, such as factor A (2 levels) x factor B (3 levels), just open the variable wizard add both variables with all levels into a column each et voilà.
  If you just have 6 conditions you can also add them manually to the variable manager.
  By adjusting the repeat field you can also set how often each conditions is repeated. But have a look on this step in the tutorial. It explains pretty much everything I just told you.

  Good luck,

  Eduard

  
• cjp87

  January 2015 edited 3:01PM

  Hi, I'd like to add some clarification to the question here. What we're trying to accomplish is to have a way to define the order in which these six conditions will occur on a subject-by-subject basis.

  How it's currently set up, there is a loop that contains six variables (the names of the conditions) which will select more loops from a sequence as each variable is called, going into that particular condition. This can be set up sequentially or randomly.

  

  We would like to be able to manually set the order of those conditions prior to the selection loop. That way we can counterbalance for ordering effects across participants by producing an incomplete counterbalance design. Is there an easy way to do this, or would it just be better to create a different program and reorder them sequentially for each participant?

  Thanks for any help.
• cjp87

  January 2015 edited 3:01PM

  We decided to just create multiple versions of the program and change the ordering in the sequential loop. For a lower number of participants, this seemed the easiest route.
• eduard

  January 2015 edited 3:01PM

  Hi,

  Indeed, your solution is probably the easiest if you have only a few subjects. However, just for sakes of completion, here is another way:
  In general, I think the variable manager is not very convenient to use for your design. It'd be better if you defined your conditions in an inline_script by hand, for instance in a list. If you also need to have full (manual) control over the order, you can include a form_text_inputin the beginning of each experiment, in which you can add the order of the blocks. Of course, you'll have to process the stored string a bit further, but this shouldn't be too hard.

  Good luck,

  Eduard

  
• shotguncarver

  January 2020

  Hi Peeps,

  I have a Stroop experiment (congruent vs in-congruent words, which are shown at random order in each condition, IV-1) and 3 musical conditions (IV-2)

  1: No music

  2: Jazz music (no lyrics)

  3: Rap music (rich in rhyming lyrics)

  I have setup a within-participant design (repeated measures), as I want each participant to participate in each condition, as I am testing to whether Rap music will increase the Stroop effect vs Jazz (which is known to decrease). During my literature review I had discovered Rap music has never been tested in the Stroop effect, its generally Jazz or classical music.

  DV = Reaction times to correct results.

  Question: I require each participant to do the practice trial first, and then I want the three music conditions in random order, how do I do this?

  Regards

  Paul :)
• shotguncarver

  January 2020

  
  
• eduard

  February 2020

  Hi Paul,

  Can you be a little more specific? What is the problem?

  The experiment you describe is quite simple in its basic set up (in fact not different from the beginner's tutorial on the Opensesame documentation. The only added element is the sampler item that has to start playing the music in the beginning of a trial. Why don't you get started on the paradigm, and turn back here on the forum once you run into specific issues?

  
  

  Good luck,

  Eduard

  (btw, there are also a couple of stroop implementations here on the forum)