Maybe the struggling students just couldn’t read, suggested one teacher. A few teachers administered informal diagnostic tests the following week and reported back. The students who couldn’t write well seemed capable, at the very least, of decoding simple sentences. A history teacher got more granular. He pointed out that the students’ sentences were short and disjointed. What words, Scharff asked, did kids who wrote solid paragraphs use that the poor writers didn’t? Good essay writers, the history teacher noted, used coordinating conjunctions to link and expand on simple ideas—words like for, and, nor, but, or, yet, and so. Another teacher devised a quick quiz that required students to use those conjunctions. To the astonishment of the staff, she reported that a sizable group of students could not use those simple words effectively. The harder they looked, the teachers began to realize, the harder it was to determine whether the students were smart or not—the tools they had to express their thoughts were so limited that such a judgment was nearly impossible.