Other studies of this kind led Mrs. Barnes to conclude that children remembered items by groups; that whole groups were often omitted; that those containing most action were best remembered; that what is remembered is remembered with great accuracy; that generalities are often made more specific; that the number of details a child carries away from a connected narrative is not much above fifty, so that their numbers should be limited; and from it all was inferred the necessity of accuracy, of massing details about central characters or incidents, letting action dominate, omitting all that is aside from the main line of the story, of bringing out cause and effect and dramatizing where possible. Miss Patterson[20] collated the answers of 2,237 children to the question "What does 1895 mean?" The blanks "Don't know" decreased very rapidly from six to eight, and thereafter maintained a slight but constant percentage. Those who expanded the phase a little without intelligence were most numerous from eight to ten, while the proportion who gave a correct explanation rose quite steadily for both sexes and culminated at fourteen for girls and fifteen for boys. The latter only indicates the pupils of real historic knowledge. The writer concludes that "the sense of historical time is altogether lacking with children of seven, and may be described as slight up to the age of twelve." History, it is thought, should be introduced early with no difference between boys and girls, but "up to the age of twelve or thirteen it should be presented in a series of striking biographies and events, appearing if possible in contemporary ballads and chronicles, and illustrated by maps, chronological charts, and as richly as possible by pictures of contemporary objects, buildings, and people." At the age of fourteen or fifteen, another sort of work should appear. Original sources should still be used, but they should illustrate not "the picture of human society moving before us in a long panorama, but should give us the opportunity to study the organization, thought, feeling, of a time as seen in its concrete embodiments, its documents, monuments, men, and books." The statesmen, thinkers, poets, should now exceed explorers and fighters; reflection and interpretation, discrimination of the true from the false, comparison, etc., are now first in order; while later yet, perhaps in college, should come severer methods and special monographic study.