Examining the Effectiveness of the Optimality Theory Approaches:A Typological-comparative Analysis

The purpose of this paper is to evaluate the effectiveness of five approaches of Optimality theory, including the following subsections "Feature alignment", "Feature linking with span", "Local agreement", "Span theory" and " Agreement-by-correspondence (ABC)" in analyzing the phenomenon of rounding harmony within Iranian (Razan and Tabriz) varieties of Turkish, as well as examining the difference in language class in the presence of a typological variety, and finally evaluating the effectiveness of each approach in the event of differences. The results indicated that with the exception of Local agreement and Feature alignment approaches, the other three approaches were very effective in explaining the phenomenon of rounding harmony between the two varieties under consideration, and the ability to explain the phenomenon of rounding harmony had the same inclusion in all three approaches. Moreover, despite the similarity of both varieties in the fields of syntax, morphology, etc., they were different in terms of typology; it means that each of them was categorized in a separate hypothetical language class A, B; which can be well proved in optimality analytical tableaux. The results indicated that in addition to the two approaches introduced by Sasa (2009), the Span theory was also quite successful in explaining the phenomenon of rounding harmony. This confirmed the innovation of the present study.