Edward William Dolch, Ph.D. published a book in 1948 called "Problems in Reading" which devoted an entire chapter on sight words. Dolch identified a need for a sight word list as opposed to a standard word list which typically contains over five hundred words. He concluded that the most essential words will be repeated on the “best” lists of words used by children.
He obtained the following three lists:
A list published by a committee in an international kindergarten union that contains the words children recognize prior to entering first grade (Washington, International Kindergarten Union, 1928).
A list published in A Reading Vocabulary for the Primary Grades by Arthur I. Gates. Dolch used Gates’ first 500 hundred words (New York: Teachers College, Columbia University, 1926).
A list compiled by H.E. Wheeler and Emma A. Howell in the article A First-Grade Vocabulary Study which contained 453 words most frequently found in reading material in first grade(Elementary School Journal, XXXI, September, 1930).
After comparing the three lists, he excluded nouns and selected the most common words based on frequency. In addition, he exercised professional judgment and included 27 words which were on only two of the three lists. The end result was a list of 220 words commonly referred to as sight words. He presented them according to level of difficulty, alphabetical and function or parts of speech.
The 220 words include
6 conjunctions – used to join clauses,
16 prepositions – used to introduce phrases,
26 pronouns – used to represent person or things,
34 adverbs – used to modify verbs,
46 adjectives – used to modify nouns, and
92 verbs – used to denote action.
Dolch referred to the above words as “tool” or “service” words because they are used in all writing regardless of subject matter. Dolch’s sight words represent approximately half of printed material and he encouraged every child to learn to recognize these words instantly. Many of the Dolch list words cannot be sounded out phonetically, nor can they be illustrated to add a visual cue to the learning process.
Dr. Edward Fry, was Professor Emeritus, Rutgers, The State University of New Jersey. Dr Fry was a member of the Graduate School of Education. He became an expert in teaching reading. He invented the Fry Readability Graph, which is a widely used tool for assessing the readability level of almost any type of reading material. He was on the faculty of Loyola University in LA and Rutgers University in NJ where he became a full professor. During his twenty-two years at Rutgers, he was President of the National Reading Conference, the International Reading Association, and the New Jersey Reading Association. He is a member of the Reading Teacher Hall of Fame. In 1996, Dr. Fry expanded on Dolch's sight word lists and research and published a book titled "Fry 1000 Instant Words." In his research, Dr. Fry found the following results:
25 words make up approximately 1/3 of all items published.
100 words comprise approximately 1/2 of all of the words found in publications.
300 words make up approximately 65% of all written material.