General practice in kindergarten education in the United States, by Mary Dabney Davis, Ph. D., in cooperation with the Research Committee of the Department of Kindergarten Education of the National Education Association
A 1925 United States report on kindergarten practice, written by Mary Dabney Davis for the National Education Association's kindergarten research committee and aimed at educators. The four charts plot the number of cases against clock hours in five-minute periods, showing when activities cluster across the day, with stepped histogram lines rising and falling over the morning. A designer might take the plain stepped-line graph style, with its hand-ruled axes, sparse labels and clean black line on white, as a model for minimal data graphics.
