association convention

association line

A term used in NON-LINEAR PHONOLOGY for a line drawn between UNITS on different LEVELS. The notion has been especially developed as a means of linking TIERS in AUTOSEGMENTAL PHONOLOGY. From a PHONETIC viewpoint, these lines represent temporal simultaneity (or overlap), indicating the relationship in time between the FEATURES represented at each tier, such as TONES and VOWELS. Segments which associate between tiers are considered freely associating segments; segments which do not freely associate would be ignored, in the application of an autosegmental RULE. Once an association line has been established, the association convention is used to relate the remaining features: when unassociated features (e.g. vowels and tones) appear on the same side of an association line, they are automatically associated in a one-to-one way, radiating outward from the association line. Unbroken association lines indicate associations that already exist; broken association lines (- - - -) indicate a STRUCTURAL CHANGE following a rule adding a new association. Association lines in a given representation may not cross (the ‘no-crossing constraint’). An ‘X’ (or similar convention, such as =) through an association line indicates that the line is to be DELETED by a rule. A circle round a segment means that it is not associated to any segment on the facing tier. For example, the diagram below represents a shift in a high tone from the first vowel (in the input to the rule) to the second.

Such shifts in association are known as reassociations. Multiple associations relate a unit to more than one V or C slot. Because autosegmental phonology allows a different number of elements in each tier and does not require that the boundaries between them coincide, the notion of association lines emerges as central.