Films and computer games based on books may be encouraging children to read, according to new research.
Books are no longer "standalone products", a new survey suggests, and youngsters may be trying to tackle more difficult novels above their reading age as a result.
The What Kids Are Reading report by Renaissance Learning found that nearly all of the "most-loved" books picked by children taking part in the survey this year had been turned into films, games, apps and branded products.
It concluded that if children are exposed to characters and plots through a wide range of media then they are encouraged to try reading the books on which these are based, even if they are more challenging.
In particular, the best-loved book choices of schoolchildren in Years 1-5 (aged five to 10) were on average, 2.4 years above the youngster's chronological reading age, the report claims.
This year's top reads, chosen by 426,067 children taking part in Renaissance Learning's study included six of JK Rowling's Harry Potter books, Catching Fire by Suzanne Collins which is part of the Hunger Games trilogy, The Hobbit and The Fellowship Of The Ring, both by JRR Tolkien.
Report author Professor Keith Topping said: "It is wonderful what reading highly motivated books does for children.
"For Years 1-5, children are reading favourite books at far above their chronological ability, but still maintaining a high rate of success."