Excerpt from Changes in Mental Traits With Age Determined by Annual Re-Tests Another of the earlier important studies of purely mental func tions was that of Ebbinghaus who examined several hundred school children, using mental arithmetic, memory, and his combination method. His data are given by grade or class, and by Sex, though the average age of the classes is also given. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.