Text cohesion refers to the clarity of written texts with regards to how concepts, ideas, and relations are organized together. Unfortunately, text cohesion is often ignored in the CCSS text complexity conversation since it is not part of the Lexile formula. Remember, the CCSS defines a text's complexity as the sum of quantitative measures + qualitative measures + reader and task considerations. By and large, quantitative measures are determined by a Lexile or Accelerated Reader score. The Lexile level is vaguely determined by sentence length and vocabulary (with longer sentences considered more complex). What isn't included in the Lexile formula is text cohesion, a subtle, yet powerful mediator in a text's complexity.
Characteristics of Text Cohesion
Prominent linguists Micahel Halliday and Ruqaiya Hasan (1976) deconstructed the linguistic system and noted that a text's meaning and level of difficulty can be influenced by text cohesion. The main features of cohesion include:
Referential Cohesion: This refers to words and concepts that overlap between sentences. Take the following:
- Katie is kind. Katie volunteers at the library. Katie likes volunteering at the library. (high referential cohesion)
- Katie is kind. She volunteers at the library and enjoys her work there. (low referential cohesion)
Referential cohesion considers how words and concepts must be understood by referring back (or forward) to somewhere else in the text.
PERSONAL: (think personal pronouns) he, him, they, she, them, hers
DEMONSTRATIVE: this/these, that, those, it, there,
COMPARATIVE: same as, such as, other than, otherwise, more than
ELLIPSES: I would love to eat pizza but I can’t (eat pizza) because I’m on a diet
SUBSTITUTION: What shirt are you wearing? I am wearing that one.
Texts that have less referential cohesion are more difficult to read.
Deep Cohesion: This refers to conjunctions and connective words:
TIME CONNECTIVES: after, before, earlier, while
CAUSAL: because, consequently, therefore
ADDITIVE: furthermore, moreover, additionally
LOGICAL: as a result, due to
ADVERSATIVE: however, yet, nevertheless
Texts with deep cohesion help connect the ideas, events, and information together for the reader. However, reading comprehension will suffer if a reader is unable to process the connectors.
Word Concreteness - Think vocabulary words but at either a concrete or abstract level. For example:
- Concrete words (desk, cat, school) comprise words that you can see, hear, smell, touch, taste, or feel. Easier to understand.
- Words that are abstract (vision, capitalism, exude, failure) are more difficult to see, hear, etc.
Syntactic Clarity: This is measured by the number of clauses per sentences, number of words per sentences, and the number of words that precedes the main verb of the main clause. Less clauses, words per sentences, and few number of words before the main verb indicate a simpler sentence syntax, and thus, easier to read.
- I believe Daniel was brave. (simple syntax)
- Given his courage to speak up during difficult times, I believe Daniel was brave. (complex syntax)
Readers and Text Cohesion: What the Research Tells Us
Background Knowledge Matters
A fascinating finding regarding text cohesion concerns the role of a reader's background knowledge. Interestingly, when readers have a high-degree of background knowledge about the text's topic and it is a low cohesion text, the reader comprehends it better. Researchers (McNamara & Kintsch, 1996) have referred to this as the Reverse Cohesion Effect:
low knowledge reader + high cohesion = Increased Reading Comprehension
high knowledge reader + low cohesion = Increased Reading Comprehension
So what accounts for this? Well it is hypothesized that when readers have a great deal of background knowledge on a text, they tend to be less actively engaged in comprehending it, if it is highly cohesive. However, if the text is complex and has low cohesion, the high knowledge reader is actively engaged in the comprehension process and working hard to understand it. However, readers with very little background knowledge on a topic (for example, myself reading about auto mechanics) will need a highly cohesive text in order to comprehend it better.
Comprehension Skills Matter
But what happens when we consider the reader's comprehension skills? Although less skilled readers can handle a text that is less cohesive given they have the requisite background knowledge, less skilled readers who do not have background knowledge on a topic need a cohesive text in order to make meaning from it. (O'Reilly & McNamara, 2007)
Suggestions for Readers who Struggle and Second Language Learners
So what does this research mean for educators? Here are some important considerations to remember:
- students should be given cohesive texts for day to day reading
- students need to be taught strategies for handling less cohesive texts - especially informational texts as these typically are less cohesive
- teachers must provide explicit instruction in comprehension strategies
- at least twice per week, teachers should provide lessons in close reading which require students to analyze the way a complex text is written (structure; word choice; language)
- students can learn cohesive devices during writing instruction
- comprehension assessment should always consider how the text's structure may be impeding comprehension
Tools for Measuring Text Cohesion
Since the Lexile doesn't consider text cohesion in its readability formula, it's important that teachers look at other measures of complexity. The following web-based tools were created to measure a text's cohesiveness:
In closing, as we select complex texts to use in our instruction, we should always consider that the Lexile is just one quantitative measure and should not be the sole driver of determining a text's complexity. Most importantly, it's essential that our students always strive to remain both metacognitive and metalinguistic as they read and comprehend increasingly complex texts.