I was all set to learn the secrets of teaching in my junior year of college. Instead, I didn't feel I learned much. So, later, when I needed to choose a major in graduate school, I chose educational research. There is the American Educational Research Association and I was a member for several decades.
It doesn't take long when exploring educational ideas to start thinking "individual or class". The more we study people, the clearer it becomes that from a careful point of view, each human is unique, the only one. It is expensive to deal on a case by case basis and there is always the possibility that important truths only emerge when cases, sometimes large numbers of cases, are compared. Still, attention is being paid to individuals and facts and themes involving them.
I am reading "The Dean of Shandong" by Daniel A. Bell. (The "A" in his name can be important because there are quite a few Daniel Bells.) Bell is a scholar of Confucius and explains that ancietn thinker approached teaching individually and focused on the differences and the unique themes, strengths and goals of each student. Dr. Lynn S. Kirby, my wife, titled her doctoral dissertation "A Reader-Response Analysis of Hypermedia". When I looked up 'reader-response theory', I found this:
Reader-response criticism is a school of literary theory that focuses on the reader and their experience of a literary work, in contrast to other schools and theories that focus attention primarily on the author or the content and form of the work.
I keep running into focus on individual human cases and I like that since the more I know about any one person, including me, the more I grasp that each of us is unique. I am interested in "Unique: The New Science of Human Individuality" by David Linden and similar sources like "Being You" by Anil Seth.