Why Does An Experiment Need To Be Demonstrated By A Teacher?

Just reading about experiments only provides a theoretical basis for science.  It is the preparation procedure and their protocols which provide the practical experience needed.

While learning and seeking something in class, the maximum use of our senses makes us to understand better. If a teacher is explaining some sort of experiment in class theoretically, then only one of our six senses is being involved and that is just the sense of listening.

But in other situation, when a teacher use some sort of demonstrations while letting us understand an experiment then our sense of sight also play a very vital role there. Demonstrations are very helpful for a teacher to make his students understand very well with less effort. Anther advantage is that theory makes students felling bore in class so to let them feel fresh and active demonstrations are very necessary. Students do not have much stamina to listen to the lectures for a continuous period of time. And if student is not feeling fresh then he will not be able to understand the things due to the lack of his interest.

Another need of demonstration might be the aspect of explaining it in a proper way. There might be a certain apparatus that a teacher wants his students to see and observe. So there is not a single reason of demonstrating the experiments. These reasons may vary from situation to situation.