Someone asked me about unschooling lately. My basic description is usually that it's a parent-facilitated and encouraged, yet child-led education with no parental academic agendas, expectations,or demands for their kids. The child's environment should be full and rich, with access to the resources they need which allow the development of knowledge, experience, and responsibility. The child is free to choose their own educational path, and this may include choosing to start your day with a schedule, subjects, and workbooks, to spending your day playing video and board games, or even to go (back) to school. Freedom of choice is the key. Kids need to own what they do.
But in order for unschooling to be effective, there has to be a real honest Trust that your kids will, in fact, learn everything they need to learn, when they need to learn it. This is where many parents have a hard time. Unschooling isn't something done sometimes, or with some subjects. It's a whole mindset revolving around this trust. Kids are hard-wired to be curious, creative, and diligent. Look at a preschooler. They have boundless energy and ask tons of questions and are so enthusiastic about life. Homeschoolers (and especially unschoolers) don't lose that as they grow older. School kids, on the other hand, do lose a lot of it, usually by around 8 years old - having your energy squelched, questions unanswered, a constant pressure to perform, and lack of adequate sleep, will do that to a kid.
Unschoolers learn because they truly want to learn. They go to college. They become productive adults. They love their lives. They are raised having choices. Their interests are respected and encouraged.
The concept of unschooling is a hard one to understand for many people. It is not un-parenting, it is not educational neglect, and it is certainly not a by-product of lazy parents. It is being in-tune enough with your kids to really know what they love, how they learn, what they want, and how to get it. It's filling your child's life with wonderful experiences, opportunities, and resources and letting them have the freedom to choose what they'd like to pursue further. It's your children being a part of the real outside world all the time.
Even with NY's ridiculous homeschool regulations, it works. How? The kids know what's on the IHIP. We check things off that we cover and use the rest of it as an idea starting-off point. And amazingly, at least 90% does get covered (80% is required). We can't get away from the regs, so we incorporate them into our unschooly education. It's easy and fun this way, I think. The kids love it.
So, that's my definition of unschooling. We choose this path because it works.