This is a presentation to introduce students to Toulmin’s Argumentation Scheme in the context of providing explanations in Inorganic Chemistry. It was inspired by discussions with Rick Moog at Franklin & Marshall College regarding how to encourage students to fully explain the “why” behind chemical behavior, rather than simply cite trends or equations. These slides were used to prompt a discussion about what a complete, logical explanation should include. They also served as a means of defining what is expected on quizzes and exams in response to various prompts.
• Students should recognize the difference between “how you get an answer” and a “logical explanation”.
• Students should apply this knowledge by providing the warrant in response to exam or quiz questions that ask a question and prompt “how do you know?” or “how can you tell?”
• Students should apply this knowledge by providing the backing, warrant, and data for a claim in response to exam or quiz questions that prompt “provide a logical explanation that relates to fundamental physical behavior”.
I presented this on the first day of class as an introduction to how to justify observations and predictions using theory in Inorganic Chemistry. The slides were used as prompts for an in-class discussion. All students knew that F is more electronegative than O. When they were asked why, one student answered with an excellent justification of the periodic trend based on effective charge! The stunned looks on other students faces prompted me to ask for alternative explanations, which elicited the "because F is to the right on the periodic table" answer. A survey showed that 12 out of 13 students would have provided this superficial answer. The one student who gave a detailed explanation credited the emphasis on understanding periodic trends from her AP chemistry course. This was a nice segue to the Toulmin breakdown of the components of an argument and establishing expectations for the course. I did not use the formal Toulmin terminology through the course, but I think this presentation did help students provide better explanations.
Students are given prompts on some quiz and exam questions that ask them to expand their answer with prompts like "how can you tell" or “provide a logical explanation that relates to fundamental physical behavior”. "How can you tell" questions are assessed for correct answers and correctly identifying the data and warrant for that answer. “Provide a logical explanation that relates to fundamental physical behavior” questions are assessed for the correct identification of the data and warrant, as well as a complete description of the backing.
I have not carefully assessed whether this discussion has improved student explanations, but anecdotally it seems to have done so. I have attached two example questions used on exams with expected answers. One question elicits a "how do you know" response and another elicits a "logical explanation". One very good "logical explanation" generated by a student is included.