OPTIMALITY THEORY: ISSUES AND CONSTRAINTSÂ (ENGLISH AND LINGUISTIC PROJECT TOPICS AND MATERIALS)
Introduction
The last nine decades (1920-2010) has witnessed a substantial change in the nature of research in phonological theory. This change has been marked by the development of several theoretical frameworks both linearly and nonlinearly. In the 1990s, phonological investigation reached one of the most fascinating and challenging stages as phonologists began to chart a new direction for phonological theory. Following this search, Prince and Smolensky (1993) introduced the phonological framework called Optimality Theory (OT), which encourages a deflection from rule-based to constraint-based analysis. This theory, thus, tried to account for how the natural intelligence processes utterances as it relies on well-formedness constraints, the domain of universal grammar.
Optimality theory, to an extent, appears to be one of the relatively new theories of phonology. Before now, what existed as the most viable theoretical model was the generative phonology (with its subsequent modifications), which relies a great deal on phonological rules. These rules specify the relationship between the underlying forms and the surface representations. The major function of these phonological rules, according to Oyebade (1998), is to account for changes in the value of segments. This is achieved by showing the derivational sequence or path of an item in its journey from the underlying level to the surface level.
The standard phonological rule aimed at capturing grammatical generalizations in this model appears in this format: A  B/C – D where a structural description (SD) delimits a class of inputs and a structural change (SC) specifies the operations that alter the input (Omachonu, 2011:91) Besides, one crucial assumption about this format is that any of the elements or variables (A,B,C,D) could be null or empty. And this makes it possible for the generative phonologists to capture different phonological processes within this format. It means therefore, that the central thrust of linguistic investigation, would be to focus on a system that can be used to explain or analyse inputs, according to Prince and Smolensky, in terms of ‘the possible structural descriptions of rules – and to define the operations available for transforming inputs – the possible structural changes of rules’ (cited in Omachonu, 91). This conception, as they argued, ‘has been jolted repeatedly by the discovery that the significant regularities were to be found neither in input configurations nor in the formal details of structure deforming operations, but rather in the character of the output structures…’
Prince and Smolensky went further to say that for the standard phonological rule format
A B/C – D to be worth pursuing, a theory which defines the class of possible predicates CAD (structural description) must be there, and another interesting theory which defines the class of possible operations A B (Structural Changes) must also be put in place. However, if these theories are not vigorous as indeed they might have proved to be in reality, Prince and Smolensky submitted that one must entertain or consider one of these two conclusions below:
