Research: Why Reading Practice Is Essential for Literacy Growth
More reading equates to greater vocabulary gains…
Renaissance Learning. (2019). What kids are reading: World’s largest annual study of K–12 reading habits: 2019 edition. Wisconsin Rapids, WI:
A huge gap exists between the number of vocabulary words learned by students who read for less than 15 minutes daily versus 30+ minutes per day—a difference of almost 12,000 words. Students who read under 15 minutes per day over the course of their schooling learned an estimated 1,909 new words, whereas students who read for 30+ minutes per day learned a whopping 13,866 words.
Unfortunately, the data show that the kids who read for a half hour or more daily represent less than 20% of students— about 50% of students read under the 15-minute mark.
Why is reading time so important? When kids practice reading, they are not merely repeating the words on the page. They are decoding as they read, sharpening their reading fluency, using context and other clues to determine meaning, simultaneously gaining and using background knowledge, learning about structure and voice, learning new vocabulary, and so forth.
While reading, students will acquire roughly one new vocabulary word for every 1,000 words they read (Anderson & Nagy, 1993). Thus, students learn thousands of words over the course of their schooling from reading practice alone— not from spelling tests or looking up words in a dictionary.
As a result, how much time students spend reading each day determines just how many thousands of words are learned. And learning new vocabulary, in particular, plays a key role in determining whether students understand the text they are currently reading and the texts they will encounter in the future.
… and greater gains in reading achievement In addition to monumental vocabulary growth, the more time kids spend reading, the higher they score in reading. Research has shown “reading volume is actually central to the development of reading proficiencies” (Allington, 2014) and that independent reading helps students improve achievement in reading and other areas of study (Cunningham & Stanovich, 1991; Stanovich & Cunningham, 1993).
In the 2017–2018 school year, students who read less than 15 minutes per day experienced reading achievement gains of only 3 percentile rank (PR) points (49 PR to 52 PR). Those who read 15 to 29 minutes per day started with the same average PR (49) but ended 7 points higher at 56.
Students who read 30+ minutes per day started with a slightly higher average PR of 50, and then grew 9 PRs to land at 59. These students made triple the gains of the kids who read for less than 15 minutes per day. However, only about one in six students read the 30+ minutes per day needed for maximum PR gains, while two in six kids read for 15 to 29 minutes per day.