This article reports on an experimental study that set out to investigate and compare the effectiveness of a direct and an indirect approach to data-driven learning (DDL) in facilitating Chinese learners' mastery of a challenging type of lexico-grammatical resource (i.e. hedges) in an undergraduate English-as-a-foreign-language (EFL) writing class. The study adopted a pretest/posttest/delayed posttest randomized two treatment design. The two experimental groups received, respectively, direct and indirect DDL instruction in the use of hedges in English academic writing. The direct approach involved students in conducting guided searches and analyses of target hedges in online corpora, whereas the indirect approach featured the use of corpus-informed, paper-and-pen learning tasks. Within- and between-group analyses of the participants' performances on the three tests yielded evidence of both the strengths and limitations of the two approaches. A questionnaire survey revealed the participants' favorable attitudes toward the incorporation of corpora in classroom teaching, as well as their perceptions of the affordances and constraints of DDL. The article concludes with a discussion of the present study's limitations and recommendations for future DDL research in EFL classrooms.