There may, of course, be some lessons that can properly be assigned in a moment by telling the class how much to take in advance. This is true of lessons that are only a continuation of matter with which the class are already somewhat familiar, which they know how to study, and which contains no special difficulties. For example, spelling lessons presenting no new difficulties or especially hard words; arithmetic lessons containing practice problems intended for drill, but no new topics for study; grammar lessons consisting of applications of principles or rules already mastered. But all lessons that are built upon a logical outline, or contain new or difficult principles, or involve especial difficulties of any kind should be assigned carefully and with sufficient detail to make sure that the class know how to go to work in preparing the lesson without loss of time and interest.
It is necessary, however, to observe a caution in this connection. There is some danger of assigning lessons in such a way as to render too much help, and thus relieve the pupil of the necessity of mastering it for himself. It is difficult to say whether the mistake of helping too much in the assignment, or not helping enough is the more serious. The teacher must know his class and his textbook, and then use the best judgment he has in making just such suggestions as will result in the best effort and mastery by the pupils without robbing them of the necessity for work.
The following are the chief points to be observed in assigning the lesson:--
1. Go over the lesson with the class in such a way as to give them a _bird's-eye view_ of the whole, a general idea of what the entire lesson is about, or what it is meant to teach. Sometimes this can best be done with the books open in the hands of the pupils, the teacher calling attention to the topics treated. Occasionally the teacher may himself state the aim or scope of the lesson without the use of the text. Getting this synthetic view of the lesson enables the pupil to begin study with better intelligence, and also helps him better to understand the relation of the separate parts to the lesson as a whole. In this bird's-eye view of the lesson its relation to the lesson just recited, or other previous lessons, should be brought out so as to unite the separate lessons into a continuous view of the subject.