On Wednesday, April 10, 2002, at 11:04 AM, Beruvin wrote:
> I wonder if the 'milliseconds' function would be a good and > 'serious' measure for a RT (reaction time !) ? I have used the milliseconds function a little for timing. The resolution will vary depending mostly on the OS. I get ms resolution on my OS X and Mac OS 9 (compatibility mode) on my Blue & White G3. Your greater problem is accuracy in estimating variations in time between noting the ms and creating the stimulus and between the actually key press and noting the time in the handler for the key press (or mouse down or whatever). The modern OS is doing all kinds of things that can cause variations in these times. Design your experiment accordingly. Do not refer to any controls other than the stimulus within the timing period. Always call milliseconds() in the handler of the stimulus and in the handler of the response. Avoid calling milliseconds() in functions and called handlers. (There is also something weird about the latter and milliseconds() and I haven't figured it out yet.) Any measure can be a 'serious' measure depending on your experiment goals and experiment design. Just keep yourself honest in estimating error factors. You might be able to come up with a demo that can run on multiple platforms, but for the actual experiment itself, I'd choose the fastest computer around and target it. (For me, because of observed weird behavior, I'd test everything the best I can.) Dar Scott _______________________________________________ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
