I discovered the "Keepers" series two years ago. At first I was unsure of the format, and it took me a while to appreciate all the activities, but now they are the foundation in my homeschool curriculum. The stories and activities are suitable for a wide range of ages so that they may be used for years with the same child. There is so much depth and insight to all of the Keepers books that it is a compliment to any style of homeschool. For naturalists, home schoolers, un-schoolers, classical educators or public schools - these books are absolutely a must for every child living in North America! I can't say enough about these books.