In this experiment, students in a large undergraduate biology course were first exposed to the concepts without new technical vocabulary ("jargon") in a pre-class reading assignment. Their learning of the concepts and jargon was compared with that of an equivalent group of students in another section of the same course, whose pre-class reading presented both the jargon and concepts together in the traditional manner. Both groups had the same active-learning classes with the same instructor, and then completed the same post-test. Although the two groups performed the same on the multiple choice questions of the post-test, the group exposed to concepts first and jargon second included 1.5 times and 2.5 times more correct arguments on two free-response questions about the concepts. The correct use of jargon between the two groups was similar, with the exception of one jargon term that the control group used more often. These results suggest that modest instructional changes whereby new concepts are introduced in a concepts-first, jargon-second manner can increase student learning, as demonstrated by their ability to articulate their understanding of new concepts.