This is one of the most difficult tasks that a teacher has to perform. It is sometimes hard to decide how to mark. The teacher is supposed to know, all the time, the quality and amount of work that is being done on each model on which the class is working, and as he passes from bench to bench he can so watch the work that he can easily pass his judgment on the workmanship and faithfulness of the pupil. Teachers have to accept work from some pupils that he would not accept from others. For instance, here is a boy who has inherited a strong tendency towards skillfulness in the use of tools, and it is quite easy for him to do the work in an excellent manner, but he should be kept at his very best all the time and show steady improvement. The duty of the teacher, here, would be to make the right sort of a leader of him, encouraging him to do extra work in the way of invention, and helping to teach those who need special instruction.

Here is another pupil who is naturally dull and has inherited no tendency towards skillfulness. It would be impossible for him to equal the other in his work, but if he has done his best after having been shown his deficiencies and has made another trial, his work should be accepted, even if not up to the standard of excellence that the average pupil can make.