A randomized controlled trial to test efficacy of digital enhancements of storybooks in support of narrative comprehension and word learning.

Experiments with film-like story presentations have been found to be beneficial in supporting children's story comprehension and word learning. The main goal of the current study was to disentangle the effects of visual and auditory enhancements in digital books. Participants were 99 typically developing children (41 boys and 58 girls) aged 4-6 years from two public kindergartens in Bursa, Turkey. A randomized controlled trial was conducted with a control group and four experimental conditions that included all possible combinations: static illustrations with and without music/sounds and animated illustrations with and without music/sounds. In each experimental condition, children read two different storybooks twice, each time in small group sessions of 2 or 3 children. The posttest included, apart from story comprehension, expressive and receptive vocabulary tests of book-based words. Story comprehension, not word learning, benefited from visual enhancements in digital books. Music and background sounds did not stimulate story comprehension and even had a negative effect on receptive vocabulary. To explain the findings, we refer to multimedia learning principles such as temporal contiguity. Consequences for a digital storybook format are discussed.