Immediate constituent analysis

The aim of immediate constituent analysis (IC analysis) is to bring out the hierarchical structure in the composition of a complex sign. To this end, it is assumed that a complex sign is composed in a stepwise procedure which, at each step, applies an operator to an operand. In the simplest case, there is just one operand, and the operator is a segmental sign like the operand. In this case, a binary analysis is possible in which the complex at hand can be shown to be composed of two sequential parts. That is, at each step a complex is cut into two parts. This is a binary analysis.

All the parts of a whole brought out by this analysis are its constituents. At each level, a cut separates the immediate constituents of the complex. Cuts performed at the level of parts bring out mediate constituents of the whole.

Given a complex that consists of a sequence of constituents abcd, the first cut could, in principle, yield the immediate constituents a - bcd or ab - cd or abc -d. Only one of these binary analyses is correct. The method of making the cuts correctly involves testing the paradigmatic and the syntagmatic relations. Paradigmatic relations are tested by substitution tests; syntagmatic relations are tested by permutation tests.

Substitution tests

Each x that is assumed to be a constituent is a member of a class – a grammatical category. At each level, the cut is performed in such a way that classes are maximized.

The correct IC analysis of German Ununterscheidbarkeit ‘indistinguishability’ is [ [Un- [[unter scheid-] -bar]] -keit ]. The crucial point in this example is the combination of the prefix un- with unterscheidbar. Theoretically, the analysis could be [ Un- [unterscheidbarkeit]]. This, however, would presuppose that un- can combine freely with elements of the class that Unterscheidbarkeit belongs to. To this class – the abstract common noun – belong, for instance, Heiterkeit, Ruhe and Struktur. Now it is true that un- does combine with some nouns such as Ruhe (it does not combine with Struktur). However, the far majority of the nouns that may apparently be prefixed by un- start by an adjective as first member, just like Unterscheidbarkeit. And in all these cases – Unschönheit, Unklugheit, Unsauberkeit etc. –, the adjective itself also combines with un- (unschön, unklug, unsauber). And on the other hand, if a noun whose first member is an adjective does not take the prefix un-, as for instance Heiterkeit (*Unheiterkeit), then this adjective itself does not take it either (*unheiter). This proves that it is not the noun, but the adjective that is combined with un-. Cf. also the German explanation of the same method.

Permutation tests

Assume a sequence abc and let the question be whether constituency is [[ab][c]] or [[a][bc]]. This question may be answered by a permutation test as follows:

If there is a permutation cab, then the correct constituency is obviously the former, while if there is a permutation bca, then the correct constituency is the latter. This applies, for instance, to a complex sentence with a conjunction “in the middle”, like Linda worked while Irvin slept. This has a permutation while Irvin slept, Linda worked, showing that the conjunction is a constituent of the second clause.