If you ask a class of second grade students to define readability, they will most likely shrug their shoulders and give you a puzzled look. However, if you observe their classroom routine, you will soon realize that many of their daily reading experiences are shaped by the products of readability assessments, or "leveled books." Most teachers of developing readers spend a lot of time assessing their students' reading levels, using readability formulas to measure a text's complexity,  and then trying to match students with books that are "just right" for them. So, even though young students are unaware with the term readability, they are familiar with its concept. (When I asked my daughter what the yellow, blue, and red stickers on her 2nd grade classroom books meant, she matter-of-factly replied, "Most kids are allowed to read from the yellow and blue dot bins, but then there's Jasper — he's the only kid who is allowed to read the red dot books, since he's the smartest kid in the class.")

If you flash forward to the middle school classroom where students are no longer confined to reading from assigned bins, there doesn't seem to be the same emphasis on matching reader to text — despite the fact that "two thirds of eighth graders do not read at the 'proficient' level." (NAEP Reading_2009) Most likely this shift has occurred because middle school students are usually taught by content area teachers who are expected to introduce texts such as the Bill of Rights or complicated explanations of genetics, and even if their students struggle with reading these texts, teachers are still responsible for teaching the concepts conveyed in them. Furthermore, due to time constraints and a lack of training in the teaching of reading skills, teachers are forced to convey the content through summaries or illustrations instead of expecting students to be able to independently comprehend that content.

The Common Core and Text Complexity

The Common Core State Standards (CCSS) initiative is attempting to change such reading practices among secondary school teachers and students. When researchers used a readability formula to assess the Lexile level of high school texts and compared that average to the average level of college texts, they found a significant 350-point Lexile gap (Williamson, 2006 as cited in CCSS). Acting on such findings, the creators of the Common Core realigned the grade-level bands to absorb that gap beginning in second grade. In other Words, the CCSS seeks to gradually ratchet up the reading levels of the texts used in grades 2 through 12, in the hope that future high school graduates will be better equipped to independently and proficiently read the texts they encounter in college. This gradual increase in text complexity has been dubbed the "staircase of complexity": as students climb the grades, the complexity of their reading should ideally climb along with them.

Measuring Readability and Issues of Vocabulary

So, how is the readability of a text measured? It depends on who you ask… One quantitative measurement that is frequently used by teachers, parents, and librarians to easily assess the readability level of various books and texts is the Flesch-Kincaid Grade Level Formula. Flesch-Kincaid reports a grade level score based on an algorithm that assesses two variables of a text: average sentence length (ASL) and average number of syllables per word (ASW). If you have access to a digital copy of a text, you can usually obtain the Flesch-Kincaid Grade Level "readability statistics" for a text by tinkering with the Spelling and Grammar settings in Microsoft Word.

One shortcoming of the Flesch-Kincaid Grade Level Formula is that it assesses vocabulary based only on average number of syllables: the more syllables a word has, presumably the harder a word tends to be. What Flesch-Kincaid does not take into account is how frequently a word shows up in the English language. Students often think of "big words" as being harder words, but word difficulty also boils down to exposure. Although unstoppable has four syllables and din has one, more students have been frequently exposed to the base word of unstoppable: stop (once every 52 pages), whereas din only shows up once every 829 pages. So which word is harder?

Source: Vocabulary.com Dictionary

VocabGrabber orders a text's vocabulary by relevance — namely, how frequently words show up in a particular text as opposed to how frequently they show up in the English language in general. VocabGrabber is a useful tool to complement the Flesch-Kincaid scale, since it will give readers an overview of a text's vocabulary and will prioritize words that are highly relevant to comprehension. 

How can understanding readability help me teach complex texts?

One way to help students grapple with more complex texts is to be more transparent about measurements of readability in the classroom. Reveal to students the readability of a text before reading it, and engage in meaningful discussions about what makes a text difficult. As experienced readers, students are accustomed to skipping over more difficult sentences and trying to focus on those sentences that make more sense to them. Help students resist this temptation and begin to deconstruct the reading process by beginning discussions with questions like, "What is the most difficult sentence in this text?" "What makes it difficult?"

For example, one of the Common Core text exemplars suggested for grades 6-8 is Winston Churchill's 1940 Address to Parliament "Blood, Toil, Tears and Sweat" (measuring at about the 10th-grade level on Flesch-Kincaid in Microsoft Word). Instead of summarizing the gist of Churchill's message for students or having one of your more proficient readers do the job for the rest of the class, ask students to first identify the more complex and important sentences in the text — without discussing their content. Then, isolate one of those "meaty" sentences for a close reading exercise such as annotation.

The central sentence in the following passage from Churchill's speech spans 44 words and VocabGrabber ranks seven of those words with top relevance scores of 4 or 5 (on a scale from 1-5).

You ask, what is our policy? I can say: It is to wage war, by sea, land and air, with all our might and with all the strength that God can give us; to wage war against a monstrous tyranny, never surpassed in the dark, lamentable catalogue of human crime. That is our policy.

Annotating this sentence to identify the antecedent of it ("our policy"), using VocabGrabber and Visual Thesaurus word maps to replace unfamiliar words with more familiar synonyms, and adding the word that to more explicitly connect tyranny to its modifying phrase "never surpassed in the dark, lamentable catalogue of human crime" are incremental steps that can lead struggling readers to decipher Churchill's message without relying on someone else's summary of the speech.

Guided annotation exercises can help students to become more interactive and observant readers of complex texts. And, once students begin to view a text as a collection of sentences and words, some much harder than others, they can more easily apply their decoding and inference skills to those especially challenging passages. The reward will come when students realize that they are actively making meaning from a text, instead of passively receiving someone else's interpretation.