Students confuse molecular processes concerning synthesis of macromolecules, particularly DNA, RNA and proteins. I have the students make separate lists of terms they need to know AND clues as to how to keep them separate.The students come to the board and generate the list - they pass a marker to another student to keep adding to the list. We review as a group and determine if all the terms are lined up correctly. This semester I decided to increase the use of contrasting between the processes based on our lists. While applying one process I would ask them to think about why it is not the other processes, what clues do we see, which terms fit etc.
I assessed one simple prompt on a test which asks which process is shown in the picture. The answer is RNA synthesis or transcription. In sp 15 with an n = 39, 62% provided the correct answer while in fall 15 with an n = 54, 67% provided the correct answer. I am certain this not significant but it is nice to see a bit of an improvement. My objective, however was to determine if contrasting back and forth hindered learning, it appears it did not.