You can define tinkering in part in contrast to other activities. MitchResnick, for example, talks about how traditional technology-related planning is top-down, linear, structured, abstract, and rules-based, while tinkering is bottom-up, iterative, experimental, concrete, and object-oriented. (Resnick is very big on creating toys that invite tinkering.)
The kind of iterative learning Soojung-Kim Pang references pulls knowledge from our limbs. We know more than we can tell.