http://dcherukhin.i2p/blog/guest/p/10E5CE2CAB/attachments/COR2.html
Observing and classifying Being a good observer is an important skill for budding scientists to develop. Infants and toddlers use all their senses to observe. Preschoolers begin to sort things into categories — big and small, loud and quiet, rough and smooth, to name just a few.