Correction
There is an error in the article "A Hierarchy of Drug Use in Adolescence: Behavioral and Attitudinal Correlates of Substantial Drug Use, "by Beatrix A. Hamburg, M.D., Helena C. Kraemer, Ph.D., and William Jahnke (November 1975 issue). In figure 1, page 1159, the authors inadvertently interchanged the labels of the curves representing hard liquor and tobacco usage.