Tim John’s Data-Driven Learning (DDL) is further developed as Pedagogic Processing of Corpora (PPC) in classroom language teaching. In this study, a group of ESL learners (the Experimental Group) acquire vocabulary by being exposed to a large quantity of teacher-edited language materials from the corpora. In this implementation, a free-of-charge online vocabulary inquiry system, which is user-friendly for teachers even whom are without any know-how of corpus linguistics, is applied. Another group of ESL learners (the Control Group) are taught by the conventional method. The collected data from these two groups is assessed to evaluate the new method’s effects on learners’ medium-term language awareness enhancement. The empirical evidence of medium-term effects of PPC is beneficial for making its inroad to the mainstream of pedagogy.