From 1930s to 1950s, audio-visual education was widely developed in the United States. Edgar Dale, an American educator, put forward the famous "tower of experience" theory in his book Audio-visual Method Teaching, which became the main theoretical basis of audio-visual education at that time.
According to Dell, human beings acquire knowledge mainly through two ways, one is through their own direct experience, and the other is through indirect experience. His "tower of experience" theory divides human learning experience into three categories and ten levels according to the degree of abstraction.
Direct experience with purpose; Design experience; Acting experience; Observation and demonstration; Trainee travel; Visit the exhibition; Television, movies; Still images, recording and broadcasting; Visual symbols; Symbols of words (spoken language, words).
The reason why Dell put forward the "tower of experience" theory is to let people know the way of human cognition. According to the cognitive law of human beings from simple to complex, from image to abstraction, and the combination of image and abstraction, choose reasonable learning methods to make their cognitive process conform to this cognitive law and achieve the best learning effect.
Dell's "Tower of Experience" is an intuitive analogy to illustrate that learning experience can directly participate in the gradual development process of using images instead of abstract symbols.
According to the concept of psychology, the bottom of the tower (experience of doing) can be called object intuition, the top of the tower (abstract experience) can be called language intuition, and the middle of the tower (experience of observing) can be called model intuition. Because it is not easy to highlight the essential characteristics of objective things, it is easy to attract students' attention to the non-essential aspects of things, and it is often limited by time and space.
However, the representation that language intuition relies on is the restoration of temporary connection between nerves, and the salience and reliability of the things it reflects are not as good as that of perception, so it is of great significance to abandon the short-lived simulated intuition (audio-visual experience).
Dell believes: "It is the semi-concrete and semi-abstract audio-visual teaching materials that play a powerful media role in summarizing real feelings." "Because of the audio-visual learning experience, it is easy to turn to abstract conceptualization and concrete practicality.
He also pointed out that "the more diverse the media used in teaching, the richer and stronger the concepts formed." Now the appearance of the network makes the central part of the tower more intuitive, and it is easier to turn to the two ends of the tower for abstract conceptualization and concrete realization.