The grandfather of the original instructional theory was Robert M. Gagne in 1977 with his Conditions of Learning at Florida State University's Department of Educational Research.
One of the most current trends in instructional theory is Learning Objects. There are currently many groups trying to set standards for the development and implementation of Learning Objects. At the forefront of the standards groups is the Department of Defense's (DoD)Advanced Distributed Learning (ADL) initiative with its SCORM standards. SCORM stands for Sharable Content Object Reference Model.
There is an entire vocabulary and related acronyms related to SCORM and Learning Objects.
Benjamin Bloom has also had a major influence on modern instructional theory with his Taxonomy of Education Objectives first published in 1956.
The two schools of thought in education can be considered the cognitivists and the behaviorists schools of learning.
B._F._Skinner's theories on behavior have had a huge influence on instructional theory because it can be measured scientifically. The cognitivists, though popular, have greater difficulty in demonstrating learning has taken place and therefore considered a softer side of an already soft body of science, education.
Paulo Freire's Pedagogy of the Oppressed, first published in English in 1968, had a broad influence over a generation of American educators with its critique of various "banking" models of education and its analysis of the teacher-student relationship.