There are a lot of educational theories developed in past and many of them are related also to Instructional Design.

About theories related to Instructional Design - In General

• Instructional Design Models by Ryder, M. (2004)/li>

Instructional system design

• An introduction to instructional system design by O'Neal, A.F., Fairweather, P.G., & Huh Y.H. (1988)
• Big Dog's ISD Page by Clark, D. (1995)
• Suggested Self-Study Program for Instructional Systems Development (ISD) by M. David Merrill (2000)

Component Display Theory

• Component Display Theory - Foundations of Instructional Technology by Jacobs, M. (1999)