In 1915 Dr. Leonard P. Ayres of the Russell Sage Foundation tabulated
some of the lists of words then available and made a selection of the
1,000 commonest words. This list of 1,000 words was then divided into 50
lists of 20 words each and given in the middle of the year to the
children of two consecutive grades in a number of cities. As a check,
words were taken from each of the fifty lists and recombined into new
sets of twenty words each, then sent out as tests in each of four
consecutive grades in different cities. The whole number of children
thus tested was 70,000 in 84 cities in grades II to VIII inclusive. On
the basis of this testing the Ayres Spelling Scale was organized.
The significant features of the scale are: (1) It contains only the
commonest words. (2) It gives approximately what one ought to expect
from any given grade when spelling words that are listed as equal in
spelling difficulty. (3) The determination of the difficulty of any word
was not dependent on the judgment of any one person, or group of
persons, but on the ability of a large group of children to spell those
words by writing them.
In giving the tests for the purpose of this scale it was not previously
known whether the words had been studied or not. It has been found that
testing these words after they have been carefully taught yields from 5%
to 20% higher accuracy. Because they are the most common words in our
language (Ayres found that these words comprise approximately 90% of our
writing vocabulary) they are the words which ought to be taught
carefully and thoroughly. All of these words occur in the Aldine
Vocabulary.