曲天宇

As a field， instructional design is historically and traditionally rooted in cognitive and behavioral psychology， though recently constructivism has influenced thinking in the field. This can be attributed to the way it emerged during a period when the behaviorist paradigm was dominating American psychology. There are also those who cite that， aside from behaviorist psychology， the origin of the concept could be traced back to systems engineering. The impact of each of these fields is difficult to quantify， however， it is argued that the language and the "look and feel" of the early forms of instructional design and their progeny were derived from this engineering discipline. Specifically， they were linked to the training development model used by the U.S. military， which were based on systems approach and was explained as "the idea of viewing a problem or situation in its entirety with all its ramifications， with all its interior interactions， with all its exterior connections and with full cognizance of its place in its context."  The role of systems engineering in the early development of instructional design was demonstrated during World War II when a considerable amount of training materials for the military were developed based on the principles of instruction， learning， and human behavior. Tests for assessing a learners abilities were used to screen candidates for the training programs. After the success of military training， psychologists began to view training as a system and developed various analysis， design， and evaluation procedures.

Instructional design （ID）， also known as instructional systems design （ISD）， is the practice of systematically designing， developing and delivering instructional products and experiences， both digital and physical， in a consistent and reliable fashion towards an efficient， effective， appealing， engaging and inspiring acquisition of knowledge.The process consists broadly of determining the state and needs of the learner， defining the end goal of instruction， and creating some "intervention" to assist in the transition. The outcome of this instruction may be directly observable and scientifically measured or completely hidden and assumed.There are many instructional design models but many are based on the ADDIE model with the five phases： analysis， design， development， implementation， and evaluation.

A system is a group of interacting or interrelated entities that form a unified whole.A system is delineated by its spatial and temporal boundaries， surrounded and influenced by its environment， described by its structure and purpose and expressed in its functioning.

The relationship between ID and teaching is such a group of interactive or interrelated entities. Instructional design has a decisive impact on teaching. Teaching will also form feedback on Instructional design， thus forming a unified whole and driving the overall development of teaching. ID as a system is also defined by the boundaries of space and time （Instructional design needs to take into account the timeliness， real-time， diachronic and synchronic nature of teaching， as well as the differences of teaching location and regional culture.）， surrounded by the environment and influenced by its structure and purpose description， and expressed in its function.