Bara, F., Gentaz, E., & Valente, D. (2018). The effect of tactile illustrations on comprehension of storybooks by three children with visual impairments: An exploratory study . Journal of Visual Impairment & Blindness , 112 (6), 759–765. https://doi.org/10.1177/0145482X1811200610

Students' recall of story details were investigated by comparing the effects of their being read stories with accompanying book illustration conditions, including (a) no illustrations, (b) two-dimensional illustrations, and (c) three-dimensional illustrations. 

Participants were three children with visual impairments from a "local center for visually impaired individuals" (p. 759); they were 6 years old, in grade 1 in a general education school in Switzerland. Additional demographic details, such as gender and age, as well as specifics of visual impairments, were also reported. Two students had low vision, and one had congenital blindness. All three were beginning to learn braille, and one was also learning to read print. 

The researcher measured numbers of verbal student-initiated interactions with the instructor, numbers of correct details recalled, and percentages of "correct text-exploration matches" (p. 762); that is, matches between text elements and illustrations, comparing three illustration versions. These data were observations recorded by independent observers of the videorecordings of participants interacting with the instructor. 

Grade 1 students with visual impairments verbally engaged differently while the stories were read to them when no illustrations were provided compared to the two illustration conditions. Two of the three children made no comments, and one child made only a few comments, when the story had no illustrations; in contrast, all three children interacted verbally with the story reader several times when provided either two-dimensional (2-D) or three-dimensional (3-D) illustrations. With the 2-D images, two of the children made comments or asked questions to verify words or understand the illustrations. The participants tended to verbally engage less on the 3-D images, yet when they did, they indicated understanding the illustrations rather than asking questions. One of the children had a much larger proportion of matches between hearing text being read and tactiley exploring the relevant 3-D illustrations, in comparison to the 2-D images, while the other two children had a somewhat smaller percentage of such matches with the 3-D images than with the 2-D images. Two of the three children correctly recalled about 25-35% more details in the 3-D images condition than in the 2-D images or no images conditions, while the other child recalled slightly more details with the 2-D images over the other conditions. More object transformation details were recalled when using 3-D illustrations, while character-related details and other information was recalled at similar rates across the test conditions. The researcher noted that strong conclusions could not be causally argued with small numbers of participants, yet advocated for further large scale studies to be pursued to extend the consideration of the impact of different types of illustrations on students' reading detail recall and comprehension. Limitations of the study were reported, and future research directions were suggested.