It is impossible to get the best results when pupils of twelve and eighteen are members of the same class, for they are living in two different worlds of thought. A teacher cannot hope to hold together a group in which there is such disparity of age. A working basis is (13-14), (15-17), (18-20). This is but a foundation on which to work. The correct grouping should be on a physiological basis instead of chronological. A pupil ofttimes will not fit into a group of his or her own age; physiologically, they may be a year or two in advance of the rest of the class, and are mingling through the week with an older group. Adjustments in such cases should be made so that the pupil is permitted to find his or her natural grouping. Like water, they will find their level. Under no ordinary circumstances should classes be mixed (boys and girls together). =Class Names and Mottoes= _Names._--A class name will help to create a strong and healthy class spirit, and is valuable as a means of advertising the class and its work. Some prefer to take class numbers or letters, thus recognizing their relationship to the Sunday school; others select names from the Bible to indicate their relation to Bible study; others choose names that indicate some kind of Christian service, thus committing the class to Christian work; while others take names of heroes or use Greek letters. _Mottoes._--A motto is perhaps more important than a name. It will help to place and keep before the class a definite purpose. If often repeated it will aid in producing in the class the spirit expressed in the motto. The following well-known mottoes may be suggestive: We're in the King's Business--We Do Things--The World for Christ--We Mean Business--The Other Fellow--Every Man Up--Quit You Like Men. =International Teen Age Certificate of Recognition= The International Sunday School Association, through its Secondary Division, issues a certificate, or charter of recognition. This certificate represents a minimum standard of organization for classes, which is considered practical for scholars of these ages. It gives the class the recognition of the International, State or Provincial Associations; and to the schools whose denominations add their seal and signature, or provide a joint certificate, denominational recognition as well. The certificate of the Secondary Division is beautifully lithographed, and is suitable for framing for the class room. For classes of the Intermediate age (13-16 years) an Intermediate seal is affixed, and a Senior (17-20 years) or Adult seal may be added upon the advance of the class to these departments. It can be secured by filling out the application blank at the end of this leaflet, and by sending the same, together with twenty-five cents to cover the cost, to your State or Provincial Association, or Denominational headquarters. Seals may be secured from the same sources.