[open] Stimuli randomization & rating scale plugin design

Comments

• Josh

  September 2015 edited 12:46AM

  Hi Mihailo,

  You can use so-called forms to collect your responses. Check out this page: http://osdoc.cogsci.nl/forms/ for detailed instructions (and the rating scale functions in particular).

  Previous questions about the likert scale:
  http://www.cogsci.nl/forum/index.php?p=/discussion/345/solved-likert-scale-trouble/p1

  The general idea for your experiment will be to have a sequence item in a loop item and in the loop indicate to run the sequence 32 times. In the sequence you'll have a video player item, a form that collects your response, and a logger to log the response to a save file.
  Before the loop, you want to create a list with all of your video files (which are also placed in the file pool) in the prepare phase of an inline_script, e.g.: video_list = ['video1.mp4', 'video2.mp4', 'video3.mp4']. And you also want to give that list a random shuffle:

    import random
    video_list = ['video1.mp4', 'video2.mp4', 'video3.mp4']
    random.shuffle('video_list')
  

  In the sequence, you place another inline script that will pick the video for that iteration:

    video = video_list.pop(0) # takes the first element from our shuffled list.
    exp.set('video', video) # makes item available outside of inline_script
  

  In the media player item, you simply insert [video] in the 'video file' box.

  Hope this helps.

  Cheers,

  Josh
• mantovic

  October 2015 edited 12:46AM

  Dear Josh,
  Thank you very much for your help.
  It has assisted me a lot in terms of the "logic" of the design and opened my eyes with regard to "how I should think" with Open Sesame.
  Alas, though, with the video list arranged as above, Open Sesame gives me a "Type Error" (str object does not support assignment type).
  I'm probably doing something wrong and will keep on trying.
  Thanks again for all the effort.
  Mihailo