language and care in its use, the basis of clearness at this point is
thorough mastery of the subject-matter of the questions, so that the
teacher himself understands clearly just what he means to ask.

The following illustrations show some questions that are faulty from
the standpoint of obscurity of meaning:--

What caused Lincoln to issue the Emancipation Proclamation in 1863?
(Not clear whether question means why did he issue the Emancipation
Proclamation at all, or why did he issue it in 1863 instead of at some
other time.)

What are the effects of attention to a moving object? (Not clear
whether question means effects on the person attending or the effect
which the moving of an object has in making itself seen.)

Who chased whom down what valley?

Why has a cat fur and a duck feathers?

_b. Adaptation to the age and understanding of the child._--Questions
that are perfectly clear to an adult may be hazy or incomprehensible
to a child because he does not understand the terms used in the
question, or because it deals with matters beyond his grasp. The
teacher must keep within the vocabulary of the child in formulating
his questions. Where it is necessary or desirable to introduce new
words into questions, care must be taken that the child knows fully
the meaning of the new terms. A teacher asked a class in elementary
physiology, "What measures would you take to resuscitate a person
asphyxiated with carbon dioxide?" The class all looked blank. No one
seemed to know what to do. It chanced that the superintendent was
visiting the school, and he said to the teacher, "Let me try." Then he
asked the class, "What would you do for a person who had been
smothered by breathing coal gas?" The class brightened up, and every
hand was raised indicating readiness to answer the question.

Another teacher bewildered his class by asking, "Which phenomena of
the fratricidal strife in the American Republic were most
determinative of the ultimate fate of the nation?" No one knew. Had he
asked his question in plain terms, no doubt the class could have
answered it.

In an elementary history class, a teacher propounded this question:
"What American institutions have been founded on the principle of
social democracy?" Not only the terms of the question, but the thought
also is beyond the comprehension of children. Such questions are not
only useless as a means of testing, teaching, or drilling, but serve
to confuse and d