Individualized Daily Reading Research

Anderson, Wilson, and Fielding (1988) led one of the most extensive studies of independent reading in which they investigated the relationship of reading time to reading achievement. The study found that the amount of time students spent reading independently was the best predictor of vocabulary development and reading achievement gains.

The research indicates that independent reading is probably the major source of vocabulary acquisition beyond the beginning stages of learning to read. Students who read more can learn the meanings of thousands of new words each year.

The chart below shows the high impact of independent reading time to word exposure and the percentile of reading achievement.

Percentile Independent Reading
Minutes per Day
Words Read
per Year
98 65 4,358,000
90 21.1 1,823,000
80 14.2 1,146,000
70 9.6 622,000
60 6.5 423,000
50 4.6 282,000
40 3.2 200,000
30 1.3 106,000
20 0.7 21,000
10 0.1 8,000
2 0 0