Two sides to every story: Children learn words better from one storybook page at a time by Zoe M. Flack and Jessica S. Horst
This research has been published in the Infant and Child Development Journal on 30th June 2017.
The abstract says:
Two experiments tested how the number of illustrations in storybooks influences 3.5-year-old children's word learning from shared reading. In Experiment 1, children encountered stories with two regular-sized A4 illustrations, one regular-sized A4 illustration, or one large-sized A3 illustration (in the control group) per spread. Children learned significantly fewer words when they had to find the referent within two illustrations presented at the same time. In Experiment 2, a gesture was added to guide children's attention to the correct page in the 2-illustration condition. Children who saw two illustrations with a guiding gesture learned words as well as children who had seen only one illustration per spread. Results are discussed in terms of the cognitive load of word learning from storybooks.