"Unless you have used a computer to learn something yourself, you are not in a good position to think about how it can help children learn." ~ Seymour Papert (1996) The Connected Family, p85

This statement by Seymour Papert is true both of people who promote the use of computers in schools, and those who argue against their use in schools.

Further, I suspect this is almost certainly true of any instructional strategy. You cannot effectively evaluate an instructional technique from a distance, because when you are immersed in the activity, you have a much different perspective than when you attempt to evaluate the activity without experiencing it. It is far too easy to look at a collection of data and use this to evaluate an educational practice and miss critical benefits of the practice that are invisible in your data.