Pre-existing knowledge is always a factor in how a student learns something new – it's just how we, as humans, are wired. Even babies, with their very limited knowledge, use what they already know to learn new things, such as basic concepts about spatial relationships, movement and facial expressions. Previously learned information functions as a filter through which all new information must flow. During this process it is categorized and connected – sometimes accurately, sometimes not – to fit into the existing framework of knowledge.
Knowing that all students – even our own kids – have very personalized ways of thinking about things based on prior experience and knowledge, the homeschool teacher can use it to his or her advantage in the classroom. Here are three ways that students' pre-existing knowledge can positively affect homeschool teaching.
The setting in which a child learns influences how information is processed. For instance, if you have set aside a particular room in your home for teaching or perhaps even a dedicated space where science experiments take place, that association is important to your child. It is up to you, as the homeschool teacher, to ensure that the associations with this space are positive and do everything possible to encourage investigation, exploration and "what if" questioning.
Another way you can use the learning environment to your advantage is by taking your child out on "field trips" to places associated with science and other school subjects, such as a museum. Your child's pre-existing knowledge tells him or her that this place is for both fun and education and that association is a positive one upon which you can build by using innate enthusiasm.
When teaching children, it is important that the methodology help them properly organize new information to fit with pre-existing knowledge. This helps them transfer the new information learned to future, unique situations.
This can be achieved through a building block process of learning where the student is given a strong foundation of core concepts. Only after those core concepts are firmly in place should advanced learning occur so that students know how and where to organize complex information. The solid foundation becomes the pre-existing knowledge to which new information is added over time.
And finally, the way a teacher manages the homeschool classroom (consciously or unconsciously) also has a bearing on the application of pre-existing knowledge to new concepts. Teachers who rule their classrooms strictly and do not encourage exploration set that norm. It could be that you expect so much from your children they are reluctant to ask questions when they don't thoroughly understand a concept you are teaching. When it comes to science, this is often reflected by parents setting a goal of rote memorization (the periodic table, the solar system, etc.) when it's really much more beneficial to help your kids learn scientific inquiry. When you make this the expectation in your homeschool classroom, it will come easily to your students and allow them to expect the freedom to experiment and investigate science.
Pre-existing knowledge always plays a part in learning. Homeschool teachers who discover how to take advantage of this fact by providing the right environment, a learning structure that encourages organization and a set of expectations congruent with exploration will do the greatest good in helping their children learn.