And indeed, to their credit, they don’t pretend that they know how to bring the “problematic” readers up to proficiency.

Don't stigmatise the reading of not-so-great books? I'll admit to smirking when told I don't read that much by comparison, only to hear a litany of YA novels that'd make Eragon read like Zamyatin... but don't put folks down for choosing to read for pleasure. Reading utter crap won't boost your vocab, but it's leagues (or would 'miles' be more appropriate for the modern reader?) better for you than vegetating in front of a screen.

As the students read, they must translate what they read into modern English, explaining what each passage means.

This isn't easy; going from academic to vernacular register is on par with translating from a foreign language, effort-wise. Doubly so for Dickens, who takes a page to say a sentence.

veen's mention of a vocabulary percentage is on point, as reading (in a foreign language) with comprehension is painful below 90-98%, especially if the goal is for the reader to acquire new vocabulary. It's why comprehensible input is so huge in classical languages these days (and historically, before German school reforms grammaticised it): Latin isn't difficult to read if you start with an introductory text (Orberg: Roma in Italia est. Italia in Europa est. Graecia in Europa est. Italia et Graecia in Europa sunt.) rather than introductory author (Caesar: Gallia est omnis divisa in partes tres, quarum unam incolunt Belgae, aliam Aquitani, tertiam qui ipsorum lingua Celtae, nostra Galli appellantur).