KNOWLES, Malcolm S. ,The Modern Practice of Adult Education: From Pedagogy to Andragogy, Revised and updated, Ch. IV
KNOWLES, Malcom S., Toward a Model of Lifelong Education, 1972
INFED, Teaching Learning processes
-None of the criteria of the (ideal) informal teaching-learning process is formalized; all of the criteria of the (ideal) formal teaching-learning process are formalized.
-Real teaching-learning processes can assume a specific value in the formalization continuum in every one of their characteristics.
Every teaching-learning process corresponds to a specific pattern with different degrees of formalization of its criteria. This pattern depends on time and it varies in the course of the teaching-learning process.
-In this concept, the notion of non-formal teaching-learning is unnecessary.