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Forum Newbie
Group: Forum Members
Last Login: 8/17/2007 11:39:54 AM
Posts: 2,
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| Hello, I am a total beginner and I was happy to see this forum exists, hopefully, I can learn more in time and from reading here. I will describe what I am trying to do and perhaps you can help me a bit. 1. I want to present 30 photos of faces displaying 6 emotions. (each emotion will appear 5 times). I want the order of appearance to be randomized. 2. After each picture (and a gray mask that follows) I want to show the subject a screen with a two alternative forced choice. the two alternatives will include a text label of the emotion displayed and another emotion which was not**. 3. The forced choice alternatives need to exhaust ALL pairing options - this means that for the picture of HAPPY (5 pictures) the labels would be: HAPPY ANGRY; HAPPY SURPRISE; HAPPY SAD; HAPPY AFRAID; HAPPY DUSGUST - always one correct and one incorrect. However the two-alternative choices need to apear in random order, albeit connected to the emotion they belong to [each emotion has 5 forced choice pairs]. So this means I need a double random - once for the faces pictures, and once for the forced choice alternatives, but connected within... (Hopefully you are still with me  ) 4. I need to find a way to present the forced choice pair (e.g. HAPPY SAD) so that the placement of the two emotions (right, left) will also be randomized (so that the left side will not always be the emotion which is actually correct...) Any suggestions how to implement or design would be welcomed! **[This screen has to be able to take in input - preferably from the mouse in "radio button" style. is it possible?] Yael
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Forum Newbie
Group: Forum Members
Last Login: 8/17/2007 11:39:54 AM
Posts: 2,
Visits: 8
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| Well, I guess the answer is: a lot of "inline" code in visual basic... (it works!)
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Forum Guru
Group: Moderators
Last Login: 10/30/2008 3:23:17 PM
Posts: 127,
Visits: 924
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Yael,
I realize I'm a bit late here, but I thought I would add my thoughts anyways. This can be handled via script, but it can also be handled using nested List objects. If I understand your task correctly, you would essentially need to create a TrialList with 30 levels (i.e. for all 30 stimuli). Each level would have the stimulus (e.g. the picture that will be shown), along with the two choices that will be presented during the second part of the task (i.e. two alternative forced choice).
So, for example, the first 5 levels of the TrialList would be something similar to the following:
Stimulus CorrectChoice AlternativeChoice
happy.bmp happy sad
happy.bmp happy disgust
happy.bmp happy angry
happy.bmp happy surprise
happy.bmp happy afraid
You would repeat this for each of the 6 emotions and set the TrialList to sample randomly. Each level in the TrialList would also use a nested List (i.e. by typing the name of a List object into the Nested column). This nested List would have one attribute and two levels. The attribute would be named "Location" and would store 25% on level 1 and 75% on level 2. This List should also sample randomly.
Then, you would create a Slide object with two SlideText sub-objects. One sub-object would reference the CorrectChoice attribute in its Text property, the other would reference AlternativeChoice. In addition, you will create two position attributes in the TrialList (i.e. CorrectPosition and AlternativePosition). CorrectPosition will hold the value "[Location]" (without quotes), and AlternativePosition will hold the value "[Location:1]" (without quotes). This allows these attribtues to get their values from the nested List. The sub-object displaying the "correct" text will reference the CorrectPosition attribute in its X property, the other will reference AlternativePosition. This way, the sub-objects will be positioned on the left or right of the screen randomly.
The only InLine script you will need to use is to determine if the subject responded correctly or not (depending on how you are having the subject respond).
This is a lot of instructions, so I have attached a basic sample that demonstrates how all of this works. Please let me know if you have any questions after taking a look at it.
- Matt
- Matt
PST Technical Consultant
http://pstnet.com
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