Another type of question is the one which desires appreciation as a response. This question is one of the most difficult to frame, for it must tend to inhibit the critical attitude and by means of the associations it arouses or its own suggestive power get the appreciative response. Questions of this type often call for constructive imagery as a means to the desired end. Some questions are directive in their tendency. They require as response an attitude or set of the mind. They set the child thinking in this direction rather than that. In a sense they are suggestive, but they suggest the line of search rather than the response. A final type of question is akin to the one just discussed--the question whose response is further questions. Here again the response desired is an attitude, but in this case it is more than an attitude, it is also a definite response that shall come in the form of questions. The questions of a good teacher should result in students asking questions both of people and of books. These last three types of questions are perhaps the most difficult of all. Because of their complexity and subtlety they often miss fire and fail of their purpose. Properly handled they are among the most powerful tools a teacher has. The type of question used must vary, not only with the particular group of children, and the type of lesson, but also with the subject. Questions that would be the best type in mathematics might not be so good for an art lesson. The kinds of questions used must be adapted to the particular situation.