Even if you are willing to abandon the textbook approach, many homeschoolers feel insecure determining at what level their child should be working on a science topic. Does making a model of the body systems equally satisfy learning needs of both a seven-year-old and a fifteen-year-old? Probably not.
Kathryn Stout's Science Scope helps you identify appropriate activities for different age groups within each science area. This is an extremely useful resource.
Divided into four main areas—general science, life science, earth science, and physical science—it takes specific topics under each heading, then suggests methods to use with students at primary, intermediate, junior, and senior high levels. Science Scope also makes it easy to select appropriate resources for whatever topic is chosen for study.