The point is that every scientific concept must be reduced to activities. Examples and pictures must be given. The teacher can prod the class for examples. The teacher must make sure that each concept is fully explained, by asking for a brief discussion. Any concept presented without an example and a picture (mental is okay) is a failed presentation. Encourage students to be creative to think of examples.

 

The scientific principle here is logical positivism. The only meaning scientific concepts have is the operational process of doing or observing. This is because a scientific theory is a mathematical system whose conclusions are verified experimentally or observationally. Since this is the meaning of a scientific theory, we must clearly define all scientific concepts in terms of experiments. We have to be on guard not to rely upon abstract definitions given in textbooks.