Experimental evidence for diagramming benefits in science writing

Arguing for the need for a scientific research study (i.e. writing an introduction to a research paper) poses significant challenges for students. When faced with these challenges, students often generate overly safe replications (i.e. fail to find and include opposition to their hypothesis) or in contrast include no strong support for their hypothesis (i.e. relevant, valid evidence). How can we support novice scientists in generating and defending high quality hypotheses? A long history of research supports the affordances provided by structured representations of complex information. More recently, argument diagramming has gained traction in instruction for philosophy, social studies, and law. However, its effectiveness for supporting students in science is relatively untested. The purpose of the current study was to test the effectiveness of a simple argument diagram optimized for supporting students’ research writing in psychology. Two groups of undergraduate students in research methods lab courses were randomly assigned to diagramming support or no support. In the research papers, those given diagramming support were more likely to argue for an appropriately ‘risky’ hypothesis and wrote more about the relevance and validity of cited studies. Some of these gains show signs of transfer to a second paper written later in the course that did not require use of the diagramming tool.