Corpus of High School Academic Texts (COHAT), currently of 150,000+ words, aims to make academic language instruction a more data-driven and student-centered discovery learning as a special type of Computer-Assisted Language Learning (CALL), emphasizing students' critical thinking and metacognition. Since 2013, high school English as an additional language (EAL) students at the International School of Prague (ISP) have worked with corpora to discover the patterns of English in academic contexts. The positive results of their work with corpora inspired the creation of COHAT, providing a high school level bank of exemplary academic English texts by their native and non-native peers. Our focus is on detecting patterns of correct word choice, syntax and style in student writing. [For full proceedings, see ED564162.]