“Narrow Reading” occurs when students read a set of material that is similar such as a series of books by a single author. This allows the students to become familiar with a smaller set of vocabulary, and a set of characters that repeats from story to story. Stephen Krashen has been a proponent of narrow reading. The most widely cited article is Krashen, S. (2004). The case for Narrow Reading [J]. Language Magazine, 3(5), 17-19. Other leading scholars such as Paul Nation, Anna Chang and Willy Renandya have also researched various as aspects of narrow reading and recommend it as more effective than reading a random selection of graded reading material.
The articles to date on Narrow Reading, however, mainly consider texts intended for readers at higher levels, while many of our students are at the lower end of the reading ability scale. Here is a list of books, listed by their level assignment on the MReader “Kyoto scale” which you might consider trying. Teachers are encouraged to experiment with them, perhaps having one class doing purely “narrow reading” while the other class (at the same level) reads a variety of texts. The ERF is here to assist you with your experimental design.