Matching, sorting and grading
The teacher is responsible for assessing the stage of development and preparing the environment to stimulate progress to the next. In order to be able to match and sort, children need to possess adequate physical sense organs—or learn to substitute for partial or total loss. Every new relationship envisaged and brought into being is the result of a perhaps sophisticated ability to match similar evidence, sort into coherent groups and grade into a new pattern by selecting and rejecting. The process of concept growth is known as refining or sharpening the concept, and if experiences are sufficiently varied—and another person present who can help use language—the accuracy should be increased. The refining or sharpening of a concept is the process of generalisation from the particular. The richer and more frequent the experiences of the particular, the quicker the understanding from which to construct a generalisation.