His research mainly focuses on instructional design and learning science. Robert Gagne and Leslie Briggs, in their book, Principles of Instructional Design, combined Behaviorist principles of learning with a cognitive theory of learning named Information-Processing. The focus of the latter theory in this combination was of the internal processing that occurred during a learning moment.

Here are some of his publications:

Gagné, Robert Mills, Leslie J. Briggs, and Walter W. Wager. Principles of Instructional Design. 4th ed. Fort Worth: Harcourt Brace Jovanovich College Publishers, 1992