Instruction was interpreted in the metaphor of exercise, in which the mind was thought to consist of faculties in need of exercise

The advent of scientific investigation into human and animal learning

Edward Thorndike's influence of laws of learning, his advocacy of social engineering, his advocacy of educational measurements. It led to establish education as a science

Bobbitt: the goals for schooling could be derived from an objective analysis of those skills necessary for successful living·

The design of instruction was the connection between the desirable outcomes and the planning of the instructional experience that could facilitate their acquisition.

The emergence of the concepts of objectives, individualized instruction and mastery learning

Tyler's Eight Year Study: refining the procedures for writing instructional objectives; recognizing the cyclical nature of evaluation within the process of creating instruction designed to produced specific outcomes, i.e. the recognition of the formative evaluation process

World War II: the creation and distribution of the mediated learning materials

A large number of psychologists and educators were called on to conduct research and develop training materials for the military services. Development of training materials were based on their work on instructional principles derived from research and theory on instruction, learning and human behavior.

• Robert Gagne
• Leslie Briggs
• John Flanagen

Psychologists used their knowledge of evaluation and testing to help assess the skills of trainees and select the individuals who were most likely to benefit from particular training programs à examining general intellectual, psychomotor and perceptual skills

Research and development effort directed toward education.

Emergence of the role of the instructional technologist; formation of the basic instructional development team: designer, SME and producer calling for professional development of a new field

Skinner's research into operant conditioning

Skinner's programmed instruction: behavioral objectives, small frames of instruction, self-pacing, active learner response to inserted question, immediate feedback.

Shifting education's focus to the outcome behavior of the learner instead of the process of the behavior of the teacher.

Reaffirming the feasibility of a self-pacing and mastery learning· Task analysis was first used by Air Force personnel in the early 1950s.

Bloom's Taxonomy of Educational Objectives (1956)

Articulation of the components of instructional systems and the recognition of their systems properties

Robert Gagné's The conditions of Learning (1965): a milestone that elaborated the analysis of learning objectives and the relationship between different classes of learning objectives and appropriate instructional designs

• 1965: Robert Gagné's The conditions of learning: five domains of learning outcomes: verbal information, intellectual skills, psychomotor skills, attitudes, and cognitive strategies - each of which required a different set of conditions to promote learning
• Gagne's nine events of instruction: "Gagne's working the area of learning hierarchies and hierarchical analysis also has had a significant impact on the instructional design field… Gagne indicted that skills within the intellectual skills domain have a hierarchical relationship to each other, so that in order to readily learn to perform a superordinate skill, one would first have to master the skill subordinate to it. This concept leads to the important notion that instruction should be designed so as to ensure that learners acquire subordinate skills before they attempt to acquire superordinate ones." (Reiser, 2001). A learning task analysis or instructional task analysis for identifying subordinate skills becomes a key feature in many instructional design models.

The essential features of systems, i.e. evaluation and feedback resulted in the refinement of evaluation procedures, developing criterion-referenced measures

Federal support of the instructional development: in 1957, after the launching of Sptunik by the Soviet Union, the USA government poured millions of dollars into improving math and science education. The instructional materials developed with these funds were usually written by the subject matter experts and produced without tryouts with learners.

In the mid-1960, Michael Scriven (1967) pointed to the need to try out drafts of instructional materials with learners prior to the time and the materials were in their final form. Scriven indicated that this process would enable educators to evaluate the effectiveness of materials while they were still in their formative stages and, if necessary, revise them before they were produced in their final form. Scriven named this tryout and revision process "formative evaluation", and contrasted it with what he labeled "summative evaluation", the testing of instructional materials after they are in their final form.

The broadening of the field of audiovisual instruction to embrace the larger concept of instructional development and technology.

A decade of consolidation: Proliferation of ID models

Addition of needs assessment to the collection of steps that defined the ID process

The field reached out to the literature of consulting and change agents for information to assist with its growing complexity· Graduate education programs focusing on instructional systems design grew

Existing associations of professionals were redefined: DAVI became AECT; publication of Journal of instructional development

The instructional application s of microcomputers have come to dominate

Performance technology movement, with its emphasis on front-end analysis, on-the-job performance, business results, and non-instructional solutions to performance problems, was beginning to have an effect on instructional design practice (Rosenberg, 1988, 1990; Rossett, 1990)

The growth in the utilization of instructional development by business and other non-school agencies

Merrill, Li and Jones (1990) discussed the need to develop new models of instructional design to accommodate the interactive capabilities of this technology à computers began to be used as tools to automate dome instructional design tasks

The influence of the performance technology movement: broadening the scope of the instructional design field to include analysis of the causes of performance problems and non-instructional solution

Growing interest in constructivism. The instructional principles includes:

• Solve complex and realist problems
• Examine the problems from multiple perspectives
• Take ownership of the learning process
• Become aware of their own role in the knowledge construction process (Driscoll, 2000)
• How consideration of constructivist principles can enhance instructional design practices (Coleman, Perry and Schwen, 1997; Dick, 1996; Lebow, 1993; Lin et al., 1996).

Use and development of electronic performance support systems (computer-based systems designed to provide workers with the help they need to perform certain job tasks, at the time they need that help, and in a form that will be most helpful)

• Information base
• Intelligent coaching and expert advisement systems
• Customized performance support tools that automate and greatly simplify many job tasks

Rapid prototyping: this design technique has been advocated as a means of producing quality instructional materials in less time than is required when more conventional instructional design techniques are employed

• The rapid prototyping process involves quickly developing a prototype product in the very early stages of an instructional design project
• Then going through a series of rapid tryout and revision cycles until an acceptable version of the product is produced (Gustafson & Branch, 1997a; Jones and Richey, 2000)

Use of the Internet for distance learning

• The programs cannot be online replicas of the instruction delivered in classrooms; instead such programs must be carefully designed in light of the instructional features that can, and cannot, be incorporated into Internet-based courses

Knowledge Management§ Rossett (1999): knowledge management involves identifying, documenting, and disseminating explicit and tactic knowledge within an organization in order to improve the performance of that organization.

• Current-day technologies such as database programs, groupware, and intranets allow organizations to "manage" (i.e. collect, filter, and disseminate) such knowledge and expertise in ways that were not previously possible.
• Rosenberg (2001): designing training programs vs. creating knowledge management systems
• Rossett and Donello (1999): instructional designers and other training professionals not only will be responsible for improving human performance, but also will be responsible for locating and improving access to useful organizational knowledge.
• Reiser (2001) the growing interest in knowledge management is likely to change and perhaps expand the types of tasks instructional designers are expected to undertake.