This is an excerpt from my presentation at the 2015 IATEFL conference, titled "Extensive Reading: Benefits and Implementation". It illustrates the 95% to 98% known-word threshold which research suggests is required for fluent reading with comprehension.
The excerpt is from Zombies in Tokyo by Andy Boon. If you want to access a free digital version of a similar story in this series, sign up for our newsletter here: http://eepurl.com/P8z45
The research is from: Hsueh-Chao, M. H., & Nation, P. (2000). Unknown vocabulary density and reading comprehension. Reading in a foreign language, 13(1), 403-30.; and Schmitt, N., Jiang, X., and Grabe, W. (2011). The percentage of words known in a text and reading comprehension. Modern Language Journal 95(1), 26-43.