Abstract
This article develops a multimodal model for how claims and evidence work across linguistic, numeric, and visual modes in the professional writing of environmental scientists. I coded and analyzed two reports (Bacey & Barry, 2008 Bacey , J. , & Barry , T. ( 2008 ). A comparison study of the proper use of Hester-Dendy® samplers to achieve maximum diversity and population size of benthic macroinvertebrates Sacramento Valley, California (Report No. EH08-2) . Sarcramento , CA : California Environmental Protection Agency . [Google Scholar]; Levine et al., 2005 Levine , J. , Kim , D. , Goh , K. S. , Ganapathy , C. , Hsu , J. , Feng , H. , & Lee , P. ( 2005 ). Surface and ground water monitoring of pesticides used in the Red Imported Fire Ant Control Program (Report EH05-02) . Sacramento , CA : California Environmental Protection Agency . [Google Scholar]) written by research scientists working for California's Department of Pesticide Regulation (DPR) by applying concepts from studies of argument, genre, and visual representations in science. The claim-evidence patterns show initial and summative claims as well as warrants being presented in linguistic forms; however, supporting evidence (i.e., data and backing) is found in numeric, visual, and linguistic forms. These findings highlight the need to extend Toulmin's understanding of claim-evidence relationships into a more robust multimodal model.