Default

Explanation

A default is a starting assumption used unless a relevant reason calls for another treatment. The term has different jobs in the two source contexts. In markedness, it concerns the normal or baseline member of a linguistic opposition under a stated criterion; this does not itself constitute a logical rule. In defeasible reasoning, available information licenses a provisional conclusion that further information may defeat. The common feature is the role of a starting point, not a single technical mechanism.

Movement of thought

1. Establish the context of use. 2. Make the starting assumption explicit. 3. Specify exception conditions. 4. Ask whether a classification or an inference is being revised.

Example

In an invented archive, opening is assumed on weekdays unless closure is announced. A renovation notice defeats that assumption.

Counter-test

A frequent word form is not thereby unmarked in every sense or a basis for a valid inference rule.

Scientific use case

An analysis could document default rules and exceptions while separately specifying linguistic markedness criteria.

Effect

The distinction helps prevent a habitual starting point from being treated as an exceptionless truth.

Resonance

A starting point gives direction without fixing the next step.

Distinction

Distinguish statistical majority, prescription and strict implication. Linguistic defaults and default logic require separate definitions.

Sources

• IDS grammis: Markiertheit

  Definition and examples75–80

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• SEP: Non-monotonic Logic

  Introduction and §1

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• Martin Haspelmath (2006): Against markedness (and what to replace it with)

  Author abstract only, description paragraph

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