science

Logic of argumentation

Logic of argumentation is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Logic of argumentation rather than just read about it. In short: The logic of argumentation (LA) is a formalised description of the ways in which humans reason and argue about propositions. It is used, for example, in computer artificial intelligence systems in the fields of medical diagnosis and prognosis, and research chemistry.

Key takeaways

Logic of argumentation belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Logic of argumentation to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Logic of argumentation from memory before moving on to harder problems.

Reference excerpt

The logic of argumentation (LA) is a formalised description of the ways in which humans reason and argue about propositions. It is used, for example, in computer artificial intelligence systems in the fields of medical diagnosis and prognosis, and research chemistry.

Origin of term Krause et al. appear to have been the first authors to use the term "logic of argumentation" in a paper about their model for using argumentation for qualitative reasoning under uncertainty, although the approach had been used earlier in prototype computer applications to support medical diagnosis. Their ideas have been developed further, and used in applications for predicting chemical toxicity and xenobiotic metabolism, for example.

Implementations In LA, arguments for and arguments against a proposition are distinct; an argument for a proposition contributes nothing to the case against it, and vice versa. Among other things, this means that LA can support contradiction – proof that an argument is true and that it is false. Arguments supporting the case for and arguments supporting the case against are aggregated separately, leading to a single assessment of confidence in the case for and a single assessment of confidence in the case against. Then the two are resolved to provide a single measure of confidence in the proposition. In most implementations of LA the default aggregated value is equal to the strongest value in the set of arguments for or against the proposition. Having more than one argument in agreement does not automatically increase confidence because it cannot be assumed that the arguments are independent when reasoning under uncertainty. If there is evidence that arguments are independent and there is a case for increased confidence when they agree, this is sometimes expressed in additional rules of the form "If A and B then ...". The process of aggregation and resolution can be represented as follows: T = Resolve[Max{For(Ca,x, Cb,y, ...)}, Max{Against(Ca,x, Cb,y, ...)}] where T is the overall assessment of confidence in a proposition; Resolve[] is a function which returns the single confidence value which is the resolution of any pair of values; For and Against are the sets of arguments supporting and opposing the proposition, respectively; Ca,x, Cb,y, ..., are the confidence values for those arguments; Max{...} is a function which returns the strongest member of the set upon which it operates (For or Against). Arguments may assign confidence to propositions that themselves influence confidence in other arguments, and one rule may be undercut by another. A computer implementation can recognize these interrelationships to construct reasoning trees automatically.

See also Argumentation framework Argumentation theory Logic and dialectic

References

Illustrations

Worked examples

Example 1 — a first encounter with Logic of argumentation

Start with the simplest possible case. Write down what Logic of argumentation claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Logic of argumentation before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Logic of argumentation ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Logic of argumentation

In research: Logic of argumentation appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Logic of argumentation in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Logic of argumentation is common in secondary-school and first-year university syllabi. It links to neighbouring topics Arguments, Logic, so understanding it makes those chapters shorter.
In everyday life: Look for Logic of argumentation outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Logic of argumentation in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Logic of argumentation means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Logic of argumentation out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Logic of argumentation in simple terms?

Why does Logic of argumentation matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Logic of argumentation?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Logic of argumentation.