[bobbylarrybobby]

While difficult, there are surely ways to make the scroll bar move more smoothly. For instance, you could demand that it can only change direction when the scroll direction changes. You can also use past scroll bar positions as stronger estimates of document height than text content and whatever else is being used, which would lead to more consistent (if inaccurate) scrolling as well. But as long as we're estimating things we might as well make them enjoyable to use; it's not like the user will be able to discern that the scroll bar is off by 5% anyway.