3,599 research outputs found
The Efficiency of Private Universities As Measured By Graduation Rates
It is well known that human capital is enhanced by graduation from a college or university. How efficient are such institutions in conveying this mark of human capital? Efficiency and productivity in private higher education is measured by using undergraduate graduation rates as the output, and demographic variables, the quality of the students, and the annual expenditures (adjusted for academic mission) as inputs. Tests of several models using OLS and stochastic frontier analysis confirm that private schools can increase their graduation rates by increasing focused expenditures and through more selective admissions. Estimated elasticities are reported and point toward increasing expenditures as the most responsive method. Estimate graduation efficiencies of 93.0, 91.5, and near 100% are also reported for four, five and six year graduation rates respectively. A rank correlation with the U S News and World Report 2008 rankings is consistent with our measure of relative efficiencies
Durability, Re-trading and Market Performance
Key differential structural characteristics of environments studied in previous market experiments have documented large divergences in their observed performance, particularly discrepancies in their convergence to expected equilibrium outcomes. We investigate why this should be so. The type of competitive equilibrium where a market clears at a particular price as initiated by Arrow and Debreu (1954) has long been studied in the laboratory. We refer to these experiments as Supply and Demand (SD) experiments. SD experiments are highly reduced in form: items are not re-tradable, buyers and sellers are specialized in these roles, and no second commodity, cash, is used as a medium of exchange, although cash enters as a numeraire qua reward incentive for subjects. Markets with these features that are repeated over time converge rapidly to the predicted equilibrium under a regime of strict private dispersed information on individual values that define the equilibrium predictions. In contrast, consider asset markets, in which shares can be freely re-traded against cash within and across periods, shares have well-defined common values based on common public information on expected cash “dividend” yields, and individuals are not specialized as buyers or sellers. These markets produce price bubbles that converge only with experience across repeat sessions. The prospect of re-trade, and perhaps the lack of buyer/seller specialization, results in market behavior that contrasts sharply with the perishable goods that characterize the SD experiments. Building on this background analysis we report new experiments that combine features of both environments and initiate an investigation of how commodity durability that constrains re-trading characteristics affect the observed variation in market performance.
Defining, Developing, and Using Curriculum Indicators
We begin with a brief review of the lessons learned in the Reform Up Close study, a Consortium for Policy Research in Education (CPRE) project funded by the National Science Foundation, then discuss the central issues involved in defining and measuring curriculum indicators, while noting how our approach has developed over the past 10 years (1992-2002). This is followed by a discussion about using curriculum indicators in school improvement, program evaluation, and informing policy decisions
Aging and Spectro-Temporal Integration of Speech
The purpose of this study was to determine the effects of age on the spectro-temporal integration of speech. The hypothesis was that the integration of speech fragments distributed over frequency, time, and ear of presentation is reduced in older listeners—even for those with good audiometric hearing. Younger, middle-aged, and older listeners (10 per group) with good audiometric hearing participated. They were each tested under seven conditions that encompassed combinations of spectral, temporal, and binaural integration. Sentences were filtered into two bands centered at 500 Hz and 2500 Hz, with criterion bandwidth tailored for each participant. In some conditions, the speech bands were individually square wave interrupted at a rate of 10 Hz. Configurations of uninterrupted, synchronously interrupted, and asynchronously interrupted frequency bands were constructed that constituted speech fragments distributed across frequency, time, and ear of presentation. The over-arching finding was that, for most configurations, performance was not differentially affected by listener age. Although speech intelligibility varied across condition, there was no evidence of performance deficits in older listeners in any condition. This study indicates that age, per se, does not necessarily undermine the ability to integrate fragments of speech dispersed across frequency and time
Gap Detection in School-Age Children and Adults: Center Frequency and Ramp Duration
The age at which gap detection becomes adultlike differs, depending on the stimulus characteristics. The present study evaluated whether the developmental trajectory differs as a function of stimulus frequency region or duration of the onset and offset ramps bounding the gap
Cochlear hearing loss and the detection of sinusoidal versus random amplitude modulation
This study assessed the effect of cochlear hearing loss on detection of random and sinusoidal amplitude modulation. Listeners with hearing loss and normal-hearing listeners (eight per group) generated temporal modulation transfer functions (TMTFs) for envelope fluctuations carried by a 2000-Hz pure tone. TMTFs for the two groups were similar at low modulation rates but diverged at higher rates presumably because of differences in frequency selectivity. For both groups, detection of random modulation was poorer than for sinusoidal modulation at lower rates but the reverse occurred at higher rates. No evidence was found that cochlear hearing loss, per se, affects modulation detection
Masking Period Patterns and Forward Masking for Speech-Shaped Noise: Age-Related Effects
The purpose of this study was to assess age-related changes in temporal resolution in listeners with relatively normal audiograms. The hypothesis was that increased susceptibility to non-simultaneous masking contributes to the hearing difficulties experienced by older listeners in complex fluctuating backgrounds
National Institute of Neurological Disorders and Stroke (NINDS): Advances in understanding and treating neuropathy, 24–25 October 2006; Bethesda, Maryland
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75348/1/j.1529-8027.2008.00154.x.pd
Effects of Self-Generated Noise on Estimates of Detection Threshold in Quiet for School-Age Children and Adults
Detection thresholds in quiet become adult-like earlier in childhood for high than low frequencies. When adults listen for sounds near threshold, they tend to engage in behaviors that reduce physiologic noise (e.g., quiet breathing), which is predominantly low frequency. Children may not suppress self-generated noise to the same extent as adults, such that low-frequency self-generated noise elevates thresholds in the associated frequency regions. This possibility was evaluated by measuring noise levels in the ear canal simultaneous with adaptive threshold estimation
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