Rice University-based nonprofit OpenStax, which is already changing the economics of higher education by providing free textbooks to more than 1 million college students per year, today launched a low-cost, personalized learning system called OpenStax Tutor Beta that analyzes how students learn to offer them individualized homework and tutoring.  In development for three years, the system will be available this fall for three courses: college physics, biology and sociology.  While students study using OpenStax Tutor, it  learns how they learn — what they struggle with, what helps them most — and it uses that information to offer just-in-time remediation and enrichment.  The system provides personalized assessment and spaced practice, helping students focus their studying efforts on their weak areas and remember what they learned earlier in the course.