Interactive Stories or Guided Stories is the name of an English language teaching technique developed by Mark White, a language teacher/writer.
What is an Interactive Story?
The technique consists of a story, which includes both sentences and questions so that as one student reads it to the other, the listener can respond to the questions and interact with the storyteller and the story itself by making it up as they go along.
What are they for?
The goal of an interactive story is to teach narratives in graded language (like graded readers), but orally and interactively. Each episode of the story is written in successively more complex syntax. Since the progressively more complicated sentence patterns are introduced in the context of a story, the learner can learn English grammar in context.