A Dictionary of Linguistics and Phonetics David Crystal

systematic phonemics 473
between semantic units according to criteria such as the above. A similar problem
sometimes applies in grammatical analysis, where a full ‘systemic’ statement is
difficult to establish in certain areas (e.g. adverbials, apposition), partly because
of the indeterminacy of the notions involved.
In Hallidayan linguistics, the notion of system receives a special status.
In scale-and-category grammar, it is one of the four central categories recognized
by the theory (the others being unit, structure and class): ‘systems’ are
finite sets of paradigmatically related items functioning in classes. In the later
development of this approach, systemic grammar, the notion of system is
made a central explanatory principle, the whole of language being conceived
as a ‘system of systems’. Systemic here should not be confused with ‘systematic’
(in either its general or technical uses; see below): systemic grammar is concerned
to establish a network of systems of relationships, in the above sense,
which will account for all the semantically relevant choices in the language as a
whole.
The adjective systematic is often used in linguistics in its everyday sense, but in
certain contexts (usually in relation to phonetics and phonology) it receives a
restricted definition. In generative grammar, it has been used to refer to two
levels of representation in the phonological component of the grammar:
systematic phonemic and systematic phonetic levels are distinguished, the
implication being that the terms of these analyses are being seen as in systemic
correspondence with other aspects of the grammar (e.g. the morphological
relationships between items).
system architecture A computing term used in computational linguistics,
referring to the set of superordinate principles which define the operations of a
language processing system. System architectures specify the components of
such a system, the structural relations between the components, and the way
information can be controlled as it flows from one component to another during
processing.
systematic phonemics A level of representation in generative phonology
which sets up a single underlying form capable of accounting for the phonological
variations which relate grammatical structures (e.g. words). In such
pairs of words as divine ~ divinity, obscene ~ obscenity, there is plainly a regular
relationship of some kind, but it is not an easy relationship to state explicitly.
Chomsky and Halle (see Chomskyan), in their approach to this problem, argue
that the root morpheme in each pair of words can be given a single underlying
representation (/div3n/ and /obs2n/ in the above cases), and that this, along with
the rules which relate such representations to the surface alternants, accounts
for the native-speaker’s awareness of the ‘systematic’ relationships which exist
between grammar and phonology. (Such rules also often reflect sound changes
which have taken place in the history of the language.) The units in these
representations are referred to as systematic phonemes, as opposed to the ‘autonomous’
phonemes of traditional phonemic phonology, which are established
without reference to grammatical structure. Some generative phonologists (such
as Chomsky and Halle) prefer the term ‘phonological’ to refer to this level of
representation, because of the undesirable associations of the term ‘phonemic’
with traditional phonemic theory.