Assessing the functional adequacy of children's phonological systems
This paper develops the means of assessing the effect of children's contrastively restricted phonological systems on a lexical system, that is assessing the functional adequacy of a phonological system. The concept and measure of Functional Loss (FLOSS) is proposed as a measure of the number of lexical distinctions left unsignalled in a lexical system due to the loss of contrasts in the phonological system. FLOSS provides a means of prioritizing treatment goals for therapy which aim at the elimination of homophony from children's lexical systems, and consequently from their speech. It is shown that the phonological process framework provides a suitable means for the assessment of functional adequacy by enabling one to make predictions about the potential of process combinations for FLOSS. FLOSS values calculated on the basis of the 'common' vocabulary of children (5; 11-6; 11) are also provided.