visual analog scale (VAS)

[jarvis24]

Not with a moving slider, but you could work it out if you are ok with subjects simply clicking on a point on an image-based continuum. It would be done via setting up cursor regions.

e.g., see www.empirisoft.com/directrt/help/lightgun_touchscreen_cursor.htm

[lncs]

Could you create ten bmp files (more to increase the resolution) showing the indicator bar in increments from left to right, depending on the left or right button being selected, the appropraite bmp would be selected (giving the impression that the bar is moving to the left or right)?

[jarvis24]

Hmm, not sure I'm able to picture this. However, if you are asking if you could change or update the image based on where they click, then yes. You would see brief flash equal to the trial interval, but you could set up conditional jumps.

[lncs]

I think it would be easy to conceptulize if you think about a child's flip book, the main difrence being this could scroll either up or down depending on the the arrow key that is pressed.

If this is imposble to do in DirectRt, how would it look (accepting a screen refresh bettween frames) if you had unique trial for each frame.

I have attached 11 images that could be used to make a proof of concept.

[lncs]

Did this make any sense?

if you pressed the right arrow key it would be like the flip (scrolled through) book is moving being fliped to the right and if you pressed the left arrow key it would be like the book is being fliped (scrolled through) to the left.

[jarvis24]

It did. You could do this in theory but it would be complicated and require many trials to cover the contingencies. Say you are using the 11 point scale you attached and the cursor is set in the middle (50) at the start. You would need 2 trials to follow the initial trial--one that shows it set at 40 in case "left" is pressed and one that shows it set at 60 in case "right is pressed". This is where is gets complicated. You then need to have each of those two trials followed by two such trials to handle the new contingencies. And then so, and so on. I can imagine this being done but it's hard to picture it being any fun.

I do think this would be a useful feature for DirectRT. In the mean time though (since it's currently not), I'd do it in MediaLab using the existing custom items that do this sort of thing. Or, in DirectRT, I'd go with a numeric key or mouse click that jumps to where they click (one time only) rather than trying to scroll with the arrow keys--they would be pretty easy.

Hope that helps.

[heathmatheson@dal.ca]

Hi there,

I am also attempting something similar. I have figured out how to present an image of a line. I will ask participants to click anywhere below the line (with the tails representing different extremes). I have created my cursor areas corresponding to different regions of the line.

My problem is that I can't seem to figure out a way to get the data file or the log file to tell me which area the participant has clicked (i.e. the actual value of the 'area ID'). I want them to be able to click ANY of them (say there are 10) and then know which one they have selected on every trial.

Thanks !

Heath Matheson