The Coh-Metrix Common Core Text Ease and Readability Assessor (T.E.R.A.) is a tool designed to analyze the “easability” and readability, of texts and provide useful information about text features. Most current readability measures are based exclusively on two features of text; the difficulty of the sentences (usually measured by the number of words or clauses per sentence) and the familiarity of the words (usually measured by the frequency of the words in a large database of texts). There are many readability measures and though each is slightly different, they all focus solely on the surface difficulty of the sentences and the words. Coh-Metrix T.E.R.A. is very different.

T.E.R.A. analyzes text on five components: narrativity, syntactic simplicity, word concreteness, referential cohesion, and deep cohesion. For a given text, each of these components is given an “ease” score, which shows how it compares to thousands of other texts. Foremost, T.E.R.A. affords an understanding of what makes a text cohesive (or not). What features make texts more or less cohesive varies from one text to the next. Because of this, we need to read texts closely to find those sections that are less cohesive. This tool can help us do that. Once these sections are found, we can work with students to help them recognize and overcome the obstacles that less cohesive texts might present.

The five components that make up the T.E.R.A. analysis are described below.

Narrativity: Narrativity seems intuitive: the more story-like a text the higher the narrativity score, and the easier the text. Though this is true, some texts will score high on narrativity and not seem very story like. Click here to see an example .

Syntactic Simplicity: Syntactic simplicity is measured through several indices such as average number of clauses per sentence, the number of words per sentence, and the number of words before the main verb of the main clause. Texts with fewer clauses, fewer words per sentence, and fewer words before the main verb will give a text a higher score for syntactic simplicity. T.E.R.A. also measures the similarity of the sentences within each paragraph. Paragraphs that contain sentences with similar structures and verb tenses are easier to read.

Word Concreteness: Concrete words (mask, spoon, forest, ammunition) are words that refer to things you can see, hear, taste, touch, feel, or smell. Abstract words (democracy, appear, success, joy) cannot easily be seen, heard, touched, felt or smelled. A text with relatively high numbers of concrete words is easier to read and will have a high word concreteness score.

Referential Cohesion: Referential cohesion is the overlap between words, word stems, or concepts from one sentence to another. When sentences and paragraphs have similar words or conceptual ideas, it is easier for the reader to make connections between those ideas. Sometimes, however, low cohesion is desirable if you want the reader to create connections to understand the text. Click here to see an example .

Deep Cohesion: Deep cohesion measures how well the events, ideas and information of the whole text are tied together. T.E.R.A. does this by measuring the different types of words that connect different parts of a text. These words are called connectives. There are different types of these connectives: time connectives such as after, earlier, before, during, while, later; causal connectives such as because, consequently, thus. Then there are additive connectives such as both, additionally, furthermore, moreover, what is more. There are also logical connectives; actually, as a result, due to. Finally, adversative connectives are words that connect two phrases or notions that on some level conflict with each other, such as “My favorite sport is baseball however I watch more football” or “Whales are not fish yet they spend their life in the water.” Some examples of adversative connectives are: but, yet, however, although, nevertheless. All of these connectives help to tie the events, ideas and information in the text together for the reader. Click here to see an example .

Conclusion: The dimensions in the T.E.R.A. analyzer are tools to help us look into a text in order to determine what might present difficulties for our students and thus how to help them. A low narrativity score means more uncommon words and possibly more information and ideas. If this is accompanied with a low concreteness score it would indicate less concrete and more abstract words. More abstract words might mean more abstract ideas as well. A low referential cohesion score means students might have trouble seeing how some sentences follow one from the other. If this is accompanied with a low narrativity score this would be even more likely. Just as low cohesion and narrativity scores might make it more difficult for students to fully understand how sentences build on each other, low deep cohesion scores might make it more difficult to comprehend how the ideas, events or information of the text as a whole fit together.

In each of these cases the tool signals what to look for as we prepare the text for our students. Used well it can help guide us to those portions of the text likely to present difficulty and thus where we want to situate our questions and our emphasis. No two complex texts are wholly alike; to prepare students for the complexity demands of the Common Core we need to regularly work with short high quality complex texts. In this way students will gradually come to recognize what makes text rich and complex and how to best absorb what these texts provide. This can only be done with teachers; the T.E.R.A. is designed to help them do this.

Flesch-Kincaid Grade Level

In addition to the 5 component scores, T.E.R.A. provides an estimate of a passage grade level using the Flesch-Kincaid Grade Level readability formula (Kincaid, Fishburne, Rogers, & Chissom, 1975). Traditional readability formulas such as the Flesch-Kincaid have been used for decades to provide educators with an estimate of the difficulty of a text in relation to the grade level or reading ability of the reader. In T.E.R.A., the Flesch-Kincaid Grade Level is computed using a combination of the length of the sentences and the number of letters in the words [(.39 * sentence length) + (11.8 * word length) - 15.59]. This grade level estimate correlates highly with other common readability formulas.

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Consider the second paragraph of the Learned Hand piece taken from page 124 of Appendix B in the Common Core State Standards.

What then is the spirit of liberty? I cannot define it; I can only tell you my own faith. The spirit of liberty is the spirit which is not too sure that it is right; the pirit of liberty is the spirit which seeks to understand the mind of other men and women; the spirit of liberty is the spirit which weighs their interests alongside its own without bias; the spirit of liberty remembers that not even a sparrow falls to earth unheeded; the spirit of liberty is the spirit of Him who, near two thousand years ago, taught mankind that lesson it has never learned but never quite forgotten; that there may be a kingdom where the least shall be heard and considered side by side with the greatest. And now in that spirit, that spirit of an America which has never been, and which may never be; nay, which never will be except as the conscience and courage of Americans create it; yet in the spirit of that America which lies hidden in some form in the aspirations of us all; in the spirit of that America for which our young men are at this moment fighting and dying; in that spirit of liberty and of America I ask you to rise and with me pledge our faith in the glorious destiny of our beloved country.

Hand’s repetition of “spirit of liberty” or “spirit” throughout the paragraph makes it easier for the reader to absorb the meaning of each new example. This repetition of the same word or phrase makes it high in referential cohesion. The concept is clearer than if he had instead repeated the pronoun “it” throughout, used terms such as “this idea” or “this notion”, or a combination of these.

In contrast, again from Learned Hand, consider the line below. It is from the second sentence of the first paragraph.

Some of us have chosen America as the land of our adoption; the rest have come from those who did the same.

It takes some processing on the part of the reader to see that “the rest” are the descendents of those who chose America as the land of their adoption. If Hand had instead written something like: Some of us have chosen America as the land of our adoption; the rest of us are the descendents of those who made this choice.

The overlap of words (us) and word forms (chosen, choice) makes this revised sentence easier for the reader to process. It is important to note that the overlap in referential cohesion can be between adjacent sentences, sentences farther apart or both as with the “spirit of liberty” example.

The less referential cohesion a text has, the more difficult it is too read. When we use texts that score low in “referential cohesion ease” we need to find the examples of low cohesion, in much the same way I did with the Learned Hand example above, and show them to our students. Teaching students to recognize these sections of the text and how to deal with them will help make them better readers. This is why an understanding of referential cohesion is important, and why this tool can help us. What makes texts less cohesive, however, varies from one text to the next. Because of this we need to read texts closely to find those slices of the text that are less cohesive. Once found we need to work with students to help them recognize these and overcome the obstacles they present.

Consider the selection below from Appendix B in the Common Core State Standards (A Short Walk through the Pyramids and through the World of Art; page 93). The connectives and their type are bolded.

At Giza, a few miles north of Saqqara, sit three great pyramids, each named for the king exts that sh – during (temporal) whose reign it was built. No other buildings are so well known, yet (causal) the first (temporal) sight of them sitting in their field is breathtaking. When (temporal) you walk among them, you walk in a place made for giants. They seem too large to have been made by human beings, too perfect to have been formed by nature, and when (temporal) the sun is overhead, not solid enough to be attached to the sand. In the minutes before (temporal) sunrise, they are the color of faded roses, and (additive) when the last rays of the desert sun touch them, they turn to amber. But (adversative) whatever the light, their broad proportions, the beauty of the limestone, and the care with which it is fitted into place create three unforgettable works of art. What do we learn about art when we look at the pyramids? First, (temporal) when (temporal) all of the things that go into a work at the pyramids? of the limestone, and the care with whn object that has a certain spirit, and we can call that spirit harmony. The pyramids are harmonious because (causal) limestone, a warm, quiet material, is a cordial companion for a simple, logical, pleasing shape. In fact (additive), the stone and the shape are so comfortable with each other that the pyramids seem inevitable – as though (additive) they were bound to have the form, color, and texture that they do have.

Not all connectives provide equal support. The first sentence is an example.

At Giza, a few miles north of Saqqara, sit three great pyramids, each named for the king – or Pharaoh – during (temporal) whose reign it was built

It would be difficult to convey the notion that the pyramids were built during the reign of the leader they were named after without using a temporal connective. The time element, the idea that the two events (the building of the pyramids and the reign of the Pharaoh they were named after) were simultaneous is central to understanding the sentence. It is not however a difficult notion, nor is it essential to the main point of the paragraph.

The last sentence however provides an example of connectors offering more support:

In fact (additive), the stone and the shape are so comfortable with each other that the pyramids seem inevitable – as though (additive) they were bound to have the form, color, and texture that they do have.

“In fact” signals the reader that more information is coming, making it more likely that the reader will realize that “the stone and the shape are so comfortable with each other” further develops the idea of the pyramid’s harmony. Similarly “as though” signals the reader to look for yet more about the pyramid’s harmony, making it more likely the reader will grasp the author’s intention that the harmony of the pyramids was “bound to happen.” Each connector in this case provided support for the reader to enhance the understanding of the pyramid’s “spirit harmony”; the difficult notion that this spirit is the essence of art.

When the analyzer reveals a text to be low in deep cohesion, we need to teach students to notice where comprehension might be breaking down (monitor their comprehension carefully), because they will have to supply more of the connections for themselves.

Comprehension is more likely to break down when students fail to process those connectors that provide essential information. The two connectors in the previous example sentence illustrate this.

When there are more connectives and when the text calls for those connectives, the deep cohesion ease score will be higher. It should be noted though, that in some texts authors might include many of these connectors because the topic is unfamiliar to students and the relationships are complex. Thus a high score for deep cohesion does not mean the text is necessarily easy. The other scores will likely reflect this, so it is important to always be mindful of the interplay of the different dimensions of complexity that T.E.R.A. examines.