Phonological Development in Hearing Children of Deaf Parents

Phonological development in hearing children of deaf parents Dr. Diane Lillo-Martin 5/9/2010 The researcher wishes to determine the significance of a unique linguistic environment on the effects of phonological development. The research examines whether 3 hearing children of deaf parents, hereafter referred to as CODAs, have inconsistencies, as compared to children in a typical linguistic environment, in their syllable structure, phonological processes or phonemic inventories. More specifically, the research asks whether their speech is more consistent with children of typical environments or more similar to children with phonological delays or disorders or articulation disorders. After the examination of these three components to a child's phonological development, it can be concluded that the linguistic environment of CODA children does not negatively hinder their phonological language development.

The Directional Distance Function and Measurement of Super-Efficiency: An Application to Airlines Data

Lovell and Rouse (LR) have recently proposed a modification of the standard DEA model that overcomes the infeasibility problem often encountered in computing super-efficiency. In the LR procedure one appropriately scales up the observed input vector (scale down the output vector) of the relevant super-efficient firm thereby usually creating its inefficient surrogate. An alternative procedure proposed in this paper uses the directional distance function introduced by Chambers, Chung, and Färe and the resulting Nerlove-Luenberger (NL) measure of super-efficiency. The fact that the directional distance function combines features of both an input-oriented and an output-oriented model, generally leads to a more complete ranking of the observations than either of the oriented models. An added advantage of this approach is that the NL super-efficiency measure is unique and does not depend on any arbitrary choice of a scaling parameter. A data set on international airlines from Coelli, Perelman, and Griffel-Tatje (2002) is utilized in an illustrative empirical application.