Understanding your pottery materials is essential
if you want to have control of them. This includes not only knowing their best characteristics and performance, but also their worst and most temperamental. Just like humans, every material(clay, glaze, colourant, raw material etc.) has its own character and will not be identical in performance to others. PLEASE KEEP THIS IN MIND.
Some information I found amongst my collected pieces of paper, and something I do understand now having worked with clay for some time, but never seen it this way before.
So yeah, it is a good idea to keep a technical diary or logbook to record experiments.