Clarification of duration of flashing or flickering (Success Criteria 2.3.1)

Is the duration of the flashing or flickering (i.e., more than one second of time) a factor in determining accessibility compliance to WCAG 2.0 See Success Criteria 2.3.1 http://www.w3.org/TR/WCAG20/#seizure "... do not contain anything that flashes more than three times in any one second period..." In my special case example, there is a slightly less than 1 second duration of 3 flashes in an Adobe Flash image at the top of a draft Shanghai EXPO 2010 page. WARNING - currently it flashes 3 times for slightly less than one second, then repeats several seconds later. see http://fr.expo2010.cn/indextest.htm Assuming the developer adds a capability to stop the repeating Adobe Flash movie, is it still a problem because it flashes 3 times, regardless of the duration (e.g., 1 second, 10 seconds, etc.)? Or does it need to flash more that 3 times a second of time for more that 1 second of duration? The "Understanding Guidelines 2.3" further mentions: "likely to cause seizure when viewed even for a second or two." see http://www.w3.org/TR/UNDERSTANDING-WCAG20/seizure.html metrics to consider: Frequency, Duration, and Size (the text only really address frequency and size, not duration) frequency: (or interval) more than 3 flashes per second of time? (3 to 50 Hz) duration: more than one second duration of time? if it flashes more than 3, but for less than 1 second, is it a problem? size: 341 x 256 pixel block or larger - see http://www.w3.org/TR/WCAG20/#general-thresholddef Since my example only flashes 3 times and not more than 3, and it soon may change to not repeat - Guidelines 2.3 says "more than three", then I think I do not have a problem, but I'm not sure - hence the question to the list. Your informed opinions welcomed. I also believe the text and explanation can be simplified. For example: 1. by addressing the three different metrics; frequency, duration, and size. 2. by addressing the lower and upper limits of each. For example, if the frequency is 40 times in a second, but only lasts 1 second or less, regardless of size it may be hardly noticeable and not be a problem. 3. add some more common passing and failing examples. The two existing ones are good. Regards, Phill Jenkins,
Is the duration of the flashing or flickering (i.e., more than one second of time) a factor in determining accessibility compliance to WCAG 2.0
        See Success Criteria 2.3.1 http://www.w3.org/TR/WCAG20/#seizure
        "... do not contain anything that flashes more than three times in any one second period..."

In my special case example, there is a slightly less than 1 second duration of 3 flashes in an Adobe Flash image at the top of a draft Shanghai EXPO 2010 page.  

WARNING - currently it flashes 3 times for slightly less than one second, then repeats several seconds later.
        see http://fr.expo2010.cn/indextest.htm

Assuming the developer adds a capability to stop the repeating Adobe Flash movie, is it still a problem because it flashes 3 times, regardless of the duration (e.g., 1 second, 10 seconds, etc.)?  Or does it need to flash more that 3 times a second of time for more that 1 second of duration?

The "Understanding Guidelines 2.3" further mentions: "likely to cause seizure when viewed even for a second or two."
        see http://www.w3.org/TR/UNDERSTANDING-WCAG20/seizure.html

metrics to consider: Frequency, Duration, and Size (the text only really address frequency and size, not duration)
        frequency:         (or interval) more than 3 flashes per second of time? (3 to 50 Hz)
        duration:        more than one second duration of time? if it flashes more than 3, but for less than 1 second, is it a problem?
        size:                341 x 256 pixel block or larger - see http://www.w3.org/TR/WCAG20/#general-thresholddef

Since my example only flashes 3 times and not more than 3, and it soon may change to not repeat - Guidelines 2.3 says "more than three", then I think I do not have a problem, but I'm not sure - hence the question to the list.  Your informed opinions welcomed.

I also believe the text and explanation can be simplified.  For example:
1. by addressing the three different metrics; frequency, duration, and size.  
2. by addressing the lower and upper limits of each.  For example, if the frequency is 40 times in a second, but only lasts 1 second or less, regardless of size it may be hardly noticeable and not be a problem.  
3. add some more common passing and failing examples.  The two existing ones are good.  

Regards,
Phill Jenkins,