Vocabulary knowledge is one of the most important elements of reading comprehension. Text coverage is the proportion of known words in a given text. We hypothesize that text comprehension increases exponentially with text coverage due to network effects and activation of prior knowledge. In addition, the lexical threshold hypothesis states that…

We used a design-based research model to examine a historical literacy intervention in Grade 6 classrooms. This article describes the results across 2 separate instructional cycles and for students grouped into 4 categories: (a) high-achieving students (n = 23 and n = 24 for Cycle I and Cycle II, respectively), (b) average-achieving students (n =…