The nature and functions of instructional design theory is best understood when the theory is viewed as a collection of multiple theoretical perspectives that inform and impact 1) the design process as a whole and 2) its many separate sub-processes. With this in mind, Richey et al (2011) identify at least six different theoretical perspectives (i.e. content domains) from which to view the ID field. Although each domain impacts instructional design processes in various ways, the wise practitioner should always remember that the domains often overlap and should use this knowledge effectively.

The nature of instructional design theory is threefold, consisting of the collective ingenuity of those researchers who study the ID field, theoretical advancements that occur in related disciplines, and the problems, issues, and solutions that have historically defined the field of instructional design. In general, a theory provides an “empirically-based explanation of events that identifies all relevant variables and their relationships” (Richey et al., 2011). In addition, it has the unique quality of seeking the attainment of truth as an overarching goal, as opposed to practice, which seeks to attain truth only as a means to an end. In the case of ID theory, however, the lines are blurred.

In the field of instructional design, which John Dewey (1910) called a “linking science”, ID theory aims to not only discover truth, but more importantly, to have that truth applied toward the improvement of practice. Likewise, whereas theory affects practice, further theory is shaped by practitioner experience as well.

In line with Richey et al’s (2011) view that instructional design is “the science and art of creating detailed specifications for the development, evaluation, and maintenance of situations which facilitate learning and performance”, the essential function of instructional design theory is to effectively inform and improve this science and art called instructional design.

Hoover and Donovan (1995) indicate four functions of theory in social science research, of which ID theory is situated. These functions include: “providing patterns for the interpretation of data, linking one study with another, supplying frameworks within which concepts and variables acquire special significance, and ability to interpret the larger meaning of findings”. Since the field of instructional design draws from many related disciplines and applies across many diverse contexts, the structural, explanatory, and predictive roles inherent to ID theory is crucial.