Ausubel coined the process call, subsumption, which is the process by which new knowledge is included into concepts already existing in memory. One of the two ways this new knowledge is included into prior concepts is through correlative subsumption. In contrast to derivative subsumption, the second way of including new knowledge, correlative subsumption takes new information, and rather than just appending the concept, actually changes the entire concept. I think of it more like an upgrade, rather than a simple add-on.
For example, I enjoy animals and have learned a lot about animals since I was a kid (I used to want to be a vet for many years as a child). In particular, I know a good deal about dogs and basic training. What I didn’t know was much about showing dogs, dog agility and obedience competition. I got a puppy back in May with the idea of showing her, though I had little idea what that would mean or entail. I read some books and went online to read about it, but learned the most when I had my two dog show experiences this past month. My puppy is six months old, and I showed twice in the puppy category. I was clueless pretty much going in, but I know a lot more now both from my reading and my experience. So my knowledge about dogs has had an upgrade. I went from Dogs 1.583 to Dogs 2.0.