STATISTICALLY VALID: Here's one way college students studying an intro to statistics might save money: the nonprofit, 20 Million Minds Foundation, headed by former Calif. state senator, Dean Florez, is making available an e-textbook, Collaborative Statistics, available for free, via Kno. The ebook is chockfull of videos, applets and other interactive features and can be used via a web browser or on an iPads. The foundation aims to produce open source textbooks for the top 25 courses taken by US undergraduates.