Parts of an Argument
Persuasive essays are often arguments. This form of communicating is a central practice of scientists. Helping students construct strong and complete arguments is easier when we use graphic organizers, such as the Toulmin framework (see Toulmin, 1958). However, this is just one way to examine arguments. Other ways include argument mapping (see Walton, 2013) or rhetorical analyses (see Prelli, 1989).
Aristotle described two types of arguments: dialectical (using premises, which the audience may not necessarily accept, to support a conclusion) and demonstrative/ demonstration (using accepted premises to support a conclusion). These two types of arguments, obviously, require different types of persuasive strategies. To be persuasive an arguer (speaker or writer) must establish ethos (credibility), pathos (affect), and logos (rational logic). These attributes can be established using multiple strategies.
Aristotle described two types of arguments: dialectical (using premises, which the audience may not necessarily accept, to support a conclusion) and demonstrative/ demonstration (using accepted premises to support a conclusion). These two types of arguments, obviously, require different types of persuasive strategies. To be persuasive an arguer (speaker or writer) must establish ethos (credibility), pathos (affect), and logos (rational logic). These attributes can be established using multiple strategies.
evidence
Remind students that "data" can be drawn from multiple sources, including inquiry laboratory activities, reading material, class lectures and discussion, and personal experiences. "Qualifiers" are necessary to provide context for how the data support a "claim." If the "claim" is about a scientific phenomenon then only objective data should be used to support the claim. However, if the "claim" is about a socio-scientific issue, then it is common for a broader range of data to be used to support the claim. For example, students may draw on personal knowledge or moral beliefs and principles to support their claims. A question I think we must ask ourselves is, "what COUNTS as evidence?" Do we only accept evidence that results from Western Modern Scientific practices or do we accept evidence from Traditional (ecological) Knowledge?
reasoning
An argument's reasoning is grounded in the backing and warrants used. "Backing" and "warrants" are often missing from less sophisticated arguments that elementary and middle school students construct. In fact, these aspects of written discourse are not always obvious (or explicit) in the written discourse of scientists. Science teachers should encourage their students to consider what these components are and how to explicitly write about these. "Backing" often includes facts or assumptions upon which the argument rests, and "warrants" describe the type of reasoning used to connect the backing to the main stem of the argument (data --> claim). If the assumptions are grounded in principles and morals, then the reasoning used will likely be moral reasoning. If the argument is free of opinions and subjective statements, and if the backing material presented is centered on scientific facts, then it is likely that scientific reasoning is being used. A question that I think is important for natural scientists and science teachers to pose (to their students and to themselves) is "what is scientific reasoning? how do we recognize it in writing?"
arguing about socioscientific issues
If students are writing about socio-scientific issues, it is likely that they will draw on multiple types of backing and reasoning to support their claims. For example, if someone states that fertilizer use on farms should be decreased because nitrogen run-off is partially responsible for hypoxic rivers and dead zones, they may provide backing/warrants that center on nutrient cycling/scientific reasoning as well as backing/warrants that center on responsibility to care for "the commons"/ moral reasoning.
Lynn Gilbert (a 7th grade science teacher-research partner) and I created the following graphic organizer to help students organize evidence from reading material. Students placed a copy of this graphic organizer in their science notebooks and recorded any type of evidence they thought was relevant from their laboratory readings/activities, class discussions, and assigned reading.
Lynn Gilbert (a 7th grade science teacher-research partner) and I created the following graphic organizer to help students organize evidence from reading material. Students placed a copy of this graphic organizer in their science notebooks and recorded any type of evidence they thought was relevant from their laboratory readings/activities, class discussions, and assigned reading.
analyzing data sources
Teachers need to help students take time to evaluate their data as they construct their argument. Not all data gathered will support the claim that the student wants to make. Lynn and I created the following graphic organizer to help students consider what their claim was in response to a query. We were not concerned with a "right answer" to the query. Rather, we were more interested in helping students evaluate what data were appropriate for their arguments.
rebuttals
Rebuttals are statements that indicate the writer knows that there are other possible arguments. When students provide data to support rebuttals and still explain why their own claims are stronger and more valid, then the argument is considered more complete. Helping students navigate this part of an argument is essential because scientists often discuss alternative hypotheses one by one before explaining how their data support a particular hypothesis or claim. Lynn and I developed the graphic organizer (below) to help her students consider rebuttals for their final essay.
Prelli, L.J. (1989). A Rhetoric of Science: Inventing scientific discourse. University of South Carolina Press.
Sadler, T.D. & Zeidler, D.L. (2005). The significance of content knowledge for informal reasoning regarding socioscientific issues: applying genetics knowledge to genetic engineering issues. Science Education, 89, 71–93.
Toulmin, S. (1958). The Uses of Argument. Cambridge, U.K.: Cambridge University Press.
Wallace, C.S., Hand, B. & Prain, V. (2004). Writing and Learning in the Science Classroom. Dordrecht, The Netherlands: Kluwer Academic.
Walton, D.N. (2013). Methods of argumentation. Cambridge, UK: Cambridge University Press.