An argument is valid if the truth of all its premises forces the conclusion to be true. An argument is valid if it would be inconsistent for all its premises to be true and its conclusion to be false. An argument is valid if its conclusion follows with certainty from its premises.

Valid: an argument is valid if and only if it is necessary that if all of the premises are true, then the conclusion is true; if all the premises are true, then the conclusion must be true; it is impossible that all the premises are true and the conclusion is false. Invalid: an argument that is not valid.

Deductive arguments

There are three basic structures or types of argument you are likely to encounter in college: the Toulmin argument, the Rogerian argument, and the Classical or Aristotelian argument. Although the Toulmin method was originally developed to analyze arguments, some professors will ask you to model its components.

The two major types of arguments are deductive and inductive arguments.

Brockriede’s Six Argument Characteristics

• Inferential leap. This is a change in beliefs, either leaping to a new one or deepening an existing one.
• Perceived rationale.
• Competing claims.
• Uncertainty regulation.
• Confrontation risk.
• Shared frame of reference.
• See also.

In argument, evidence refers to facts, documentation or testimony used to strengthen a claim, support an argument or reach a conclusion.

Types of strong evidence Strong evidence may include: Statistics. Studies. Quotes (from subject matter experts, from articles or reports by credible sources)

adjective [ADJECTIVE noun] Hard evidence or facts are definitely true and do not need to be questioned.

Weak Evidence: • Presents an argument, but it does not completely. make sense. • The evidence does not change the audience’s. thinking.