Bound-morpheme generalization by children with SLI: is there a functional relationship with accuracy of response to training targets?

We investigated whether limited bound-morpheme generalization (BMG) by preschool children with SLI is functionally related to limited learning of training targets (words, affixed forms). Thirty children with SLI and 30 age-/gender-matched controls participated in the study. Production probes revealed a dissociation between learning and generalization performance. In addition, the number of children who achieved criterion-level BMG increased abruptly during an additional instructional experience with new training targets. These findings suggest that positive evidence of a bound morpheme's generalizability to different vocabulary stems benefits BMG. Furthermore, they suggest that limited BMG reflects problems not with the storage or access of specific trained facts but with the extraction and extension of the linguistic pattern (e.g., regularity, "rule") instantiated in the learning targets.

Interferometric back focal plane microellipsometry.

We present a technique for ellipsometric analysis of materials with high lateral resolution. A Michelson-type phase-shifting interferometer measures the phase distribution in the back focal plane of a high numerical aperture objective. Local measurements of the ellipsometric parameter delta are performed over the entire spectrum of angles of incidence. We show that delta is to leading order linearly proportional to the phase change on reflection of normally incident light. We furthermore invert the Fresnel reflection equations and derive expressions for the real and imaginary parts of the refractive index as functions of the phase change on reflection and the reflectivity at normal incidence, both of which are measurable with the same apparatus. Hence we accomplish local measurements of the refractive indices of our samples. Determination of the phase change on reflection permits correction of interferometric topography measurements of heterogeneous specimens.