Three studies were conducted to determine the validity of the idea that adult literacy students have greater reading potential (and thus can learn in much shorter periods of time) than school children who score at comparable levels to the adults on standardized reading tests, and that adults are more efficient learners than such children. The results indicated that (1) marginally literate men (MLM) reading at the fifth grade level on a standardized reading test performed comparably to typical fourth and fifth grade students on tests of comprehension by auding and reading when the materials were presented at 128 words per minute; (2) MLM reading near the fifth grade level performed more poorly than typical fifth graders on tests of learning from audio-visual materials; (3) MLM showed approximately 0.5 to 1.0 years of reading potential on an auding and reading test; (4) MLM in a military job-related reading program of 6-weeks' length showed a median gain of 0.7 grade levels in general reading and 1.6 levels in job-related reading--there was no relationship of reading potential to gain. From these findings it was concluded that one should not assume that adult literacy students will perform better or learn more quickly than children at comparable reading levels. It was also decided, however, that adults learned job-related reading more quickly than general reading skills. (KC)