Having more than one illustration per page in children's books hinders vocabulary learning among toddlers, a study has found.

While publishers look to produce ever more colourful and exciting texts to entice buyers, University of Sussex in UK have shown that too many illustrations on a page results in poorer word learning among pre-schoolers.

The findings present a simple solution to parents and nursery teachers for some of the challenges of pre-school education and could help in the development of learning materials for young children.

“Luckily, children like hearing stories, and adults like reading them to children. But children who are too young to read themselves don't know where to look because they are not following the text. This has a dramatic impact on how well they learn new words from stories,” said Zoe Flack, doctoral researcher at University of Sussex.

The researchers read storybooks to three-year-olds with one illustration at a time or with two illustrations at a time, with illustrations introducing the child to new objects that were named on the page.

They found that children who were read stories with only one illustration at a time learned twice as many words as children who were read stories with two or more illustrations.

In a follow-up experiment, researchers added a simple hand swipe gesture to guide the children to look at the correct illustration before the page was read to them. They found this gesture was effective in helping children to learn words when they saw two illustrations across the page.

“This suggests that simply guiding children's attention to the correct page helps them focus on the right illustrations, and this in turn might help them concentrate on the new words,” Flack said.

“Our findings fit well with Cognitive Load Theory, which suggests that learning rates are affected by how complicated a task is,” she said.

“In this case, by giving children less information at once, or guiding them to the correct information, we can help children learn more words,” she added.

“Other studies have shown that adding 'bells and whistles' to storybooks like flaps to lift and anthropomorphic animals decreases learning,” said Jessica Horst, from the University of Sussex.

“But this is the first study to examine how decreasing the number of illustrations increases children's word learning from storybooks,” said Horst.

“This study also has important implications for the e- Book industry. Studies on the usefulness of teaching vocabulary from e-Books are mixed, but our study suggests one explanation is that many studies with e-Books are only presenting one illustration at a time,” she added.

The research was published in the journal Infant and Child Development.