The challenge then for students becomes how of get there from here; in other words, how
to get from their present state of vocabulary knowledge to that which will give them 95% or
more coverage. The challenge for instructors is more complicated. Given the generally poor
knowledge of English high-frequency words among students and the diversity of this knowledge
between individual students (some may have good coverage of high-frequency words; others
may have limited English vocabulary), how can an instructor target words efficiently? Direct
vocabulary teaching based on words selected by the teacher will result in inefficiencies; time will
be spent teaching words some students already know.