RHONA WISE/AFP/Getty Images Researchers from Carnegie Mellon University found that Donald Trump's speeches are, on average, geared toward a 7th-grade audience in terms of their vocabulary.

Donald Trump’s campaign speeches are written at a lower grade level than those of other leading presidential candidates, a new analysis from Carnegie Mellon University suggests.

Using a readability model known as REAP, researchers Elliot Schumacher and Maxine Eskenazi analyzed a selection of speeches from Republican candidates Ted Cruz, Donald Trump and Marco Rubio (who has since dropped out of the race) and Democratic candidates Hillary Clinton and Bernie Sanders.

The sample size was small: They analyzed five of Cruz’s speeches, six speeches by Rubio and Sanders, seven by Clinton and eight by Trump.

REAP -- which isn't an acronym, according to the researchers -- measures how often different words and grammatical structures appear within a given text, then compares them with texts that education experts have determined are at a typical reading level for a particular grade.

In terms of their vocabulary, researchers found that the speeches for Trump -- who once bragged he had "the best words" -- were, on average, at about a 7th-grade reading level. Cruz’s and Clinton’s speeches were at about an 8th-grade level, while Rubio’s speeches were just under a 10th-grade level and Sanders’ were just above it.

In terms of grammatical structure, nearly all of the candidates' speeches hovered at around a 7th-grade level, with the exception of Trump, whose speeches are full of short, declarative sentences that placed them just under a 6th-grade level.

Schumacher told The Huffington Post this does not necessarily mean that the candidates sound like middle-schoolers when they speak (though hey, they definitely do sometimes). Instead, the analysis is more about how accessible their speeches are to readers and listeners.

For instance, saying that Sanders’ speeches are at a grade 10th-grade level means he is “speaking in a way that would be reflective of a text that a 10th-grader could read easily,” Schumacher said.

What Schumacher found most fascinating was the variation between the different speeches of a single candidate, which suggests that the candidate may be tailoring his or her speaking style to specific audiences. Trump’s speeches ranged the most in terms of their grammatical complexity, while Clinton’s varied the most in terms of vocabulary.

“It’s interesting to look at how various candidates portray themselves … I think it is interesting to think about how that varies based on the situation,” he said.

An August analysis by The Boston Globe placed Trump’s campaign announcement speech at a fourth-grade level, while speeches for Clinton and Sanders were at 8th and 10th-grade levels, respectively. But the Globe's analysis used a different measure -- the Flesch-Kincaid readability test -- which measures average sentence length and the number of syllables per word.

While both Flesch-Kincaid and REAP were intended to measure written text, not spoken language, the CMU researchers believe that REAP is the more effective way to measure speech.

“When we speak, we usually use less-structured language with shorter sentences,” Schuamcher and Eskenazi wrote in their report. “So while

measures such as Flesch-Kincaid are appropriate for written speech, they are not really reflective of the structure of spoken language."

"REAP has been trained on written texts … But it concentrates on how often words and grammatical constructs are used at each grade level and less on the length of the sentence and of each word,” they added.

Editor's note: Donald Trump regularly incites political violence and is a serial liar, rampant xenophobe, racist, misogynist and birther who has repeatedly pledged to ban all Muslims -- 1.6 billion members of an entire religion -- from entering the U.S.