Effect of pictures on children’s comprehension of written text

Studies have shown that under certain conditions pictures can facilitate young children’s oral prose comprehension. Can pictures also aid comprehension when the information is presented in written form rather than orally? If so, what kinds of pictures, under what conditions? These experimenters analyzed a prose passage into 350 idea units, then interspersed throughout the text pictures depicting either the 179 main ideas or both the main ideas and the 171 nonessential details, or included no pictures. The subjects, fourth and sixth graders, wrote down all they could remember of the story immediately and again 5 days later. Pictures did facilitate both immediate and delayed recall, but only of the main ideas.