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Forum Newbie
Group: Forum Members
Last Login: 9/14/2007 3:52:27 PM
Posts: 1,
Visits: 5
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Hi Everyone,
I'm wondering if someone has seen this problem before or has any insight. I'm using E-Prime 1.2.
I'm collecting responses on an in-house response pad that interfaces with the parallel port. We have four buttons, each of which is hooked up to one pin on the parallel port. We've found that E-Prime consistently reports that one of the four buttons is 200-300ms faster than the other three, and we have eliminated the button pad and the port itself as introducing this latency differences (I can describe the troubleshooting we've done if anyone is interested).
It seems that E-Prime just reads this one pin faster than it reads the other three. Is there any reason this could be? Does anyone know if it is a constant latency difference, or a variable difference? I'm hoping it's constant so that I have a chance of recovering this RT data.
We're going to test this by using a signal generator that can produce signals at known intervals (e.g., one every second) and record it's "RT" in E-Prime. If we do this for each pin, we should be able to tell whether or not the differences between the pins are constant, and hopefully figure out away to normalize the data.
I'd love to hear the opinions of other users on this topic. Has anyone had any success using the parallel port to record responses with E-Prime?
Thanks!
Erin Mazerolle
Dalhousie University
Halifax, Nova Scotia, Canada
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