Drawings were made from Tanner's photographs illustrating five stages of development each for male genitalia, testicular size, male pubic hair, female breasts, and female pubic hair. Forty-seven females and forty-eight males aged 12-16 years indicated on questionnaires which stage they were most like, and answered other questions related to their physical development. Afterwards they were examined by physicians who had not seen their answers. Pearson correlation coefficients were 0.6 or above for the physician's observations compared with the adolescents' answers for the drawings, with the exception of testicular size. Answers to questions concerning amount of underarm hair and general development also yielded high correlations.