To illustrate how semantics and syntactics affect Lexile level, read the attached pair of excerpts. One is from Clifford the Big Red Dog by Norman Bridwell and the other is by Rene Descartes.

After reading the two selections, discuss how they are different in semantics and syntax. Semantic difficulty relates to the vocabulary included in a text. Metametrics has created a corpus of words to which other words contained in a text are compared. Words that appear less often, or are more rare, have a higher Lexile level. Syntactic difficulty refers to the complexity of sentence structure. The longer the length and the more complex a sentence, the higher the Lexile level.