Tablet Use

In an article posted on ZDNet today, results of a Nielsen report on tablet use was announced. Based on this graphic, it looks like a lot of educational activities are being done by choice.

But, as with most reports of data like this, I often find that there's some underlying assumptions. This report seems to assume that the 57% who use tablets for educational purposes weren't previously using the home computer or other devices for educational purposes. In other words, is the tablet just a replacement for other devices or options? And, if so, is it a beneficial replacement?