Overview

This model provides a structure for arguments to improve their rigour. Arguments at their root help frame a claim, but claims are used during all strands of FDCR, not just for framing.

The Process

A simplified version of Toulmin's Structure of Argument uses five main components:

• Ground: What information do we agree on that forms the basis for this argument?
• Claim: The new piece of information presented
• Evidence: Pieces of information (primary or secondary) that are relevant to the claim
• Justification: Reasoning to support the claim that draws on evidence
• Qualifier: Conditions placed on the claim

My Experience

I found that clearly structured arguments matter most for high-impact claims. Making a claim for a requirement constraint is high impact because it determines whether the idea will be considered or rejected. All our requirement constraints in Praxis II were based on Toulmin's structure.

Figure 1: One requirement from our Praxis II RFP with flaws annotated.

My challenge in forming this argument (Figure 1) was the indirectness of sources. There was no clear-cut number stated around harmful sound levels for specific types of lakes, fish species, and non-sonar machines as research was ongoing. As you remove these qualifiers, I found the connection between evidence and the claim drift further and further. In addition, I neglected an essential ground claim, that fish were specifically in the docking area, not just in Lake Ontario. Again, a conversation with the community quickly revealed fish are not present in the docking area.

Ultimately, Toulmin's Structure is a model for a more rigorous argument. The best way to evaluate an argument's rigour is to make your argument to a wide variety of people. It seems so obvious, but our team only discussed our RFP arguments internally. Following the steps of a model is not sufficient due diligence.

Checklist

• Test your argument out on the following individuals and adjust your claim until it is generally accepted or you reject it yourself. There should probably be more on this list, but I don't have enough experience and evidence to include any others.
  • Someone who knows nothing about you’re space. Can they easily accept you’re ground claims? Can they follow the logic? Is there something unclear or assumed in the argument? These people help challenge assumptions obvious to you, but not to others.
  • Someone who knows a lot about you’re space. Are the claims you’re making factually correct and reasonable? Obvious misunderstandings are revealed by deep expertise.
    • Your stakeholders often know a lot about the space. Only ask specific questions about arguments that are generally not accepted by the above two groups because acknowledging stakeholder time is important.