Instructional Technology/Instructional Transaction Theory (ITT)
Instructional Design Based on Knowledge Objects
Based on a chapter by Merrill in Reigeluth's Green Book.
What is ITT 
Merrill introduces the Instructional Transaction Theory (ITT) as an attempt to provide more precision to designing instruction for different kinds of instructional outcomes and also as an attempt to make automated instructional design possible. As a synthesis oriented theory, ITT emphasizes the integration of the components of Merrill’s Component Display Theory (CDT) into instructional transactions. An instructional transaction is all of the interactions necessary for a student to acquire a particular kind of knowledge or skill.
By describing instructional strategies as algorithms or transactions used for manipulating data structures or knowledge objects, Merill aims to provide a more precise description of the different kinds of instructional transactions required for different kinds of instructional outcomes. Building appropriate instructional transactions into instructional development tools will enable automating certain steps of the instructional design process and will increase efficiency. ITT extends Gagne's conditions of learning and Merrill's Component Display Theory so that the rules and principles involved are enough to drive automated instructional design – a computer-based system that creates instruction based on instructional parameters input by designers.
Merrill's Instructional Transactions 
An important element of ITT is called a knowledge object. Knowledge objects provide a way to represent knowledge and are used to build a set of transaction shells (instructional algorithms) to teach it (Merrill, 1996; Merrill, 2000). The transaction shells consist of rules for selecting and sequencing knowledge objects. ITT integrates these components into instructional transactions which are made up of all the interactions necessary to acquire a particular kind of knowledge or skill.
Merrill presents instructional goals for the IDENTIFY, EXECUTE, and INTERPRET transactions (the first three of his 13 instructional classes). The referenced example is an open-ended learning environment designed to teach technicians how to install or remove a double seat valve in a pipe. Merrill describes the learning environment in terms of the instructional goal it is designed to promote, the knowledge structure required by the learning environment, the general simulation engine which operates on this knowledge structure, and the learning activity of exploration. He also describes the three instructional transactions of IDENTIFY, EXECUTE, and INTERPRET. For each transaction, the instructional goal, the knowledge structure, the presentation of information to the student, the practice with feedback, and the learner guidance are presented.
The component methods of ITT illustrate a possible increase of precision with which instructional strategies can be described in the form of knowledge objects. The instructional strategies can be described as methods for manipulating the elements of knowledge objects. They enable the specification of executable knowledge, that is, they enable both tutorial and experiential instruction from the same knowledge representation.
Personal Reflections on ITT 
I believe that Instructional Transaction Theory (ITT) has enormous potential, but I am convinced that it is a method that can only be leveraged by the use of technology. A little while ago, I attempted what I thought would be a modest project using ITT. I decided to develop a blueprint for how I could teach my students to troubleshoot computer printers and printer problems in the High School computer lab. However, the many “what if” scenarios quickly became overwhelming... so many conditions, so many combinations leading to different outcomes, so many different kinds of printers. Even if I had fully developed the architecture or blueprint, it would have been so complex that no one could have used it without the help of technology. In the end, I realized that computers are much more adept than people at keeping track of the large volume of properties and conditions and running and remembering all the “what if” calculations.
I know that there are object-based, database-driven websites out there that have thousands of knowledge objects, and I know that there has been work done by the Army on how the Army can develop an object-based, “chunky” system for writing and publishing instructional doctrine. ITT makes perfect sense to me, and I think that ITT could transform instruction and instructional design.
When knowledge objects and database structures finally become standardized, we will possess the potential to have reusable, updatable components of instruction that move at the speed of the Internet. And, if instructional designers would share and allow their work to be treated as “objects” that are publicly available, then it would seem easy to generate personalized, adaptive instruction in a relatively short period of time and at minimal cost. However, there is still a lot of research and practice necessary to enable automating certain steps of the instructional design process.
Merrill, M. D. (1999). Instructional Transaction Theory ITT):Instructional Design Based on Knowledge Objects. In C. M Reigeluth (Ed.), Instructional design theories and models: A new paradigm of instructional theory. Volume II (pp. 397-424). Mahwah, NJ: Lawrence Erlbaum Associates.
Merrill, M. D. & ID2 Research Group. (1996). Instructional transaction theory: Instructional design based on knowledge objects. Educational Technology, 36(3), 30-37.
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