States, districts, and advocates are starting to demand that education companies put their money where their mouths are on student results.

The lesson of LEACHIM, a 1970s classroom robot, isn't that machines should replace teachers. It's that every child deserves to be taught at his or her own level—and technology is now making that possible.

Students who read more across genres, topics, and settings develop stronger comprehension, vocabulary, and background knowledge through repeated exposure to language, ideas, and complex texts.