The iPad measured at 6.2% lower reading speed than the printed book, whereas the Kindle10.7% slower than print. However, the difference between the two devices was not statistically significant because of the data's fairly high variability.
Thus, the only fair conclusion is that we can't say for sure which device offers the fastest reading speed. In any case, the difference would be so small that it wouldn't be a reason to buy one over the other.Speed is something we hadn't really thought about and don't have a ready answer for why this might be. It may be familiarity; perhaps once people are as used to e-reading as they are to print, these numbers might even out.
Though if it doesn't, this difference is not insignificant: if you read several dozen books a year, this difference could add up to several less read-books over the same time. Sample size here is pretty small and this is early in the game, but this is the first real study we've seen, so we thought we'd pass it along.