Nation (2014) concluded that most of the vocabulary one needs to read challenging texts in English can be acquired incidentally through voluminous reading. This study examines possible texts that second language (L2) readers can use to move from controlled-vocabulary materials such as graded readers, which go up through approximately the 4,000-word-family level, to more challenging texts such as newspapers, classic novels, and academic texts, at the 9,000-word-family level. An analysis of a set of popular fiction series books found that such books can provide a sufficient amount of input, with 98% vocabulary coverage, so as to serve as one possible “bridge” to more challenging texts
