Leonard Porter Ayres

Leonard Porter Ayres (September 15, 1879 – October 29, 1946) was an American educator, soldier, and statistician. He also held the rank of Brigadier General in the United States Army.

Ayres was born at Niantic, Conn. He received his college and graduate training at Boston, Harvard, and Columbia universities.

He began teaching in 1902 as one of the first to carry American ideas and methods to Puerto Rico. There he was appointed superintendent of schools in the districts of Caguas and San Juan, and later general superintendent of all the public schools on the island.

Returning to live in the United States, Ayres was made head of the division of statistics in the Playground Association of America. Beginning in 1908, he was prominently identified with the work of the Russell Sage Foundation, especially as chairman of the committee in charge of the Backward Children Investigation. In 1908-09 Ayres lectured on education at New York University. On behalf of the American Statistical Association in 1915 Ayres became secretary of the Joint Committee on Standards for Graphic Presentation, which was chaired by Willard C. Brinton. In 1917 he was elected as a Fellow of the American Statistical Association.

Ayres apparently tallied a count of the U.S. Army battle deaths for World War I during which, or shortly afterward, he served as a major. Ayres was recalled to active duty in 1940 with the rank of brigadier general. He retired in 1942 and was awarded the Distinguished Service Medal.

His writings on educational subjects, besides reports and contributions to periodicals, are:

• A Course of Study for the Schools of San Juan (1905)
• Medical Inspection of Schools, with Luther H. Gulick (1908)
• Laggards in our Schools (1909, 1913)
• Open Air Schools (1910)
• Seven Great Foundations (1911)
• Health Work in the Public Schools, with May Ayres (1915)
• A Measuring Scale for Ability in Spelling (1915, republished by Mott Media, Milford, Michigan 1985)

Many of his articles in educational journals have been reprinted, among them, The Effect of Promotion Rate on School Efficiency (1913).