Search the Legacy Support Archive (up to v2020)

  1. Read-only archive (2005–2024). Posting is closed. Need help with MediaLab or DirectRT 2027? Email service@empirisoft.com.

    All words · “exact phrase” · -leave out

    Advanced search

Randomly selecting a set of questions

  1. 06-05-2008, 1:47 PM#1
    JBeaudry

    Randomly selecting a set of questions

    Hi,

    I am trying to produce a questionnaire that varies the number of times you are asked a question about a particular picture. I have 60 pictures and 6 questions can be asked about each picture. For 20 of the pictures I want only 1 question asked, for another 20 I want only 3 questions asked, and for the last 20 I want all 6 questions asked. I have managed to program MediaLab to do this, however, I am having trouble randomizing properly.

    For example, in the three question condition: I would like to randomly choose which three of the six questions are shown, but also when those three questions are shown within the whole questionnaire (i.e., I don't want to show participants all three. questions for the same image at once).

    Can MediaLab do this? Here is the questionnaire I've created. Please let me know if you have any ideas.

    Thanks!
  2. 06-14-2008, 9:31 PM#2
    jarvis24 Blair Jarvis, Administrator
    I think you were on the right track with your email regarding trying this with DirectRT. Take a look at the attached input file. I've created a very simplified version that shows the logic you could use to create the fuller design you are describing. See if it makes any sense to you and let me know if you have any questions. It uses the function to recall randomly generated stimuli from other trials (e.g., ?b1t1s1) and also uses a different copy of the question files for each image so that you never get the same question twice for any given image.
  3. 06-17-2008, 2:20 PM#3
    JBeaudry
    I think I understand the file. Basically, if I have 60 pictures to show, I would need to create 60 identical "question files." Is that correct?

    I'm not sure I understand the purpsose of using the "?b1t1s1" code, though. I understand that the code tells the program to use the same item as in Block 1, Trial 1, Stimulus 1, but I still need to make a line for every trial, correct? Could you please explain the advantage of this over just entering the file names directly?

    Thanks!!
  4. 06-18-2008, 4:58 PM#4
    jarvis24 Blair Jarvis, Administrator
    Mmmmm... actually, I guess you could just enter them directly. And yes, that would be much easier!