How Sentence Difficulty Affects Reading Comprehension

Reading proficiency is one of the most important ways Voxy measures language competency. But to make learning effective, it’s essential that the difficulty level of a text closely matches the reading proficiency levels of learners. As a result, Voxy needs to determine the difficulty level of a text as well as the difficulty level of sentences within it to provide the most effective learning experience possible.

While it’s well known among educators that a learner’s comprehension of sentences affects his or her ability to understand a full text, very little attention has been paid to the difficulty level of individual sentences. Voxy recently conducted an experiment to gain a better understanding of what makes a sentence difficult, comparing conventional measurements to more complex sentence features.

Voxy discovered that traditional non-syntactic features—elements like sentence length, total number of words, and the number of low frequency words and syllables which appear less often—may provide a more accurate assessment of difficulty than syntactic features, which are more complex. Syntactic features include who/what/why/where phrases, dependent clauses, and coordinate phrases that include words like “and,” “but,” and “so” to connect different parts of a sentence.