Firsthand knowledge is gained through the direct experience, e.g., in the form of school excursions, visits to certain places, handling particular objects, doing manual work or executing a particular object.
The child learns for himself and looks for the knowledge in its natural setting. Knowledge is not told to him but he discovers it or it is revealed to him. Direct experience is a sort of natural device to aid the learning process. The child observes, thinks about and manipulates whatever falls within his direct experience. Knowledge gained is concrete and real.