Influences of Infant‐Directed Speech on Early Word Recognition

When addressing infants, many adults adopt a particular type of speech, known as infant‐directed speech (IDS). IDS is characterized by exaggerated intonation, as well as reduced speech rate, shorter utterance duration, and grammatical simplification. It is commonly asserted that IDS serves in part to facilitate language learning. Although intuitively appealing, direct empirical tests of this claim are surprisingly scarce. Additionally, studies that have examined associations between IDS and language learning have measured learning within a single laboratory session rather than the type of long‐term storage of information necessary for word learning. In this study, 7‐ and 8‐month‐old infants' long‐term memory for words was assessed when words were spoken in IDS and adult‐directed speech (ADS). Word recognition over the long term was successful for words introduced in IDS, but not for those introduced in ADS, regardless of the register in which recognition stimuli were produced. Findings are discussed in the context of the influence of particular input styles on emergent word knowledge in prelexical infants.     

ANOVA models for Brownian motion

We investigate longitudinal models having Brownian-motion covariance structure. We show that any such model can be viewed as arising from a related “timeless” classical linear model where sample sizes correspond to longitudinal observation times. This relationship is of practical impact when there are closed-form ANOVA tables for the related classical model. Such tables can be directly transformed into the analogous tables for the original longitudinal model. We in particular provide complete results for one-way fixed and random effects ANOVA on the drift parameter in Brownian motion, and illustrate its use in estimating heterogeneity in tumor growth rates.     

Indian agricultural policy: An applied general equilibrium model

A ten-sector, sequential applied general equilibrium model is formulated, estimated, and stimulated for analyzing agricultural policy choices for India until year 2000. Ten groups of consumers (five of them rural), each with its own preferences and claims on output are recognized in the model, the groups distinguished by the range of their per capita household (real) consumption expenditure. The simulations compare: four policies with respect to the compulsory purchase and subsidized distribution to consumers of a limited amount of foodgrains and four foreign trade and aid scenarios. Procuring and freely distributing 100 kgs of grain per capita per year and financing the cost through additional taxation improves income distribution with no reduction in growth. On the other hand, the same distributional policy financed by reducing investment has a negative impact on growth.     

Parametric and nonparametric confidence intervals for estimating the difference of means of two skewed populations

In this paper, we have reviewed and proposed several interval estimators for estimating the difference of means of two skewed populations. Estimators include the ordinary-t, two versions proposed by Welch [17] and Satterthwaite [15], three versions proposed by Zhou and Dinh [18], Johnson [9], Hall [8], empirical likelihood (EL), bootstrap version of EL, median t proposed by Baklizi and Kibria [2] and bootstrap version of median t. A Monte Carlo simulation study has been conducted to compare the performance of the proposed interval estimators. Some real life health related data have been considered to illustrate the application of the paper. Based on our findings, some possible good interval estimators for estimating the mean difference of two populations have been recommended for the researchers.     

The Effectiveness of Decisional Guidance: An Empirical Evaluation

Decisional guidance is defined as how a decision support system (DSS) influences its users as they structure and execute the decision‐making process. It is assumed that decisional guidance has profound effects on decision making, but these effects are understudied and empirically unproven. This paper describes an empirical, laboratory‐experiment‐based evaluation of the effectiveness of deliberate decisional guidance and its four types. We developed and used a comprehensive model consisting of four evaluation criteria: decision quality, user satisfaction, user learning, and decision‐making efficiency. On these criteria, we compared decisional guidance versus no guidance, informative versus suggestive decisional guidance, and predefined versus dynamic decisional guidance. We found that deliberate decisional guidance was more effective on all four criteria; suggestive guidance was more effective in improving decision quality and user satisfaction, and informative guidance was more effective in user learning about the problem domain, whereas dynamic guidance was more effective than predefined guidance in improving decision quality and user learning; and both suggestive guidance and dynamic guidance reduced the decision time.     

An econometric model of the agricultural sector of the Indian economy

The interrelationships between production, consumption, and stocks are studied in an interdependent framework for two groups of agricultural commodities, namely foodgrains and nonfoodgrains, with a view to obtain policy guidelines for agricultural growth. The model is formulated with aggregate information over the period 1951–1975 and both static and dynamic simulation along with multiplier analysis are carried out to assess the performance of the model. The study reveals that if there had been no PL 480 aid from the U.S. imports, foodgrain prices would have been higher than observed prices. Ex-ante forecasts to 1985 suggest some need for adequate planning with regard to stockbuilding.     

Racial and Ethnic Diversity in Senior Centers: Comparing Participant Characteristics in More and Less Multicultural Settings

The 2008 Health Indicators Project surveyed a probability sample (N = 1,870) of New York City senior center participants. Attendees of racially and ethnically diverse and nondiverse senior centers were compared across 5 domains: demographics; health and quality of life; social support networks; neighborhood perceptions and engagement; health service access/utilization. Although homogeneous and diverse center participants demonstrate similar health and quality-of-life outcomes, those from diverse centers demonstrate greater risk of social isolation, receive less family support, and more likely seek medical care from hospitals or community clinics. Implications and future directions for research, practice and policy are discussed.     

Estimating the Population Coefficient of Variation by Confidence Intervals

Several researchers considered various interval estimators for estimating the population coefficient of variation (CV) of symmetric and skewed distributions. Since they considered at different times and under different simulation conditions, their performances are not comparable as a whole. In this article, an attempt has been made to review some existing estimators along with some proposed methods and compare them under the same simulation condition. In particular, we have considered Hendricks and Robey, Mckay, Miller, Sharma and Krishna, Curto and Pinto, and also some bootstrap proposed interval estimators for estimating the population CV. A simulation study has been conducted to compare the performance of the estimators. Both average widths and coverage probabilities are considered as a criterion of the good estimators. Two real life health related data sets are analyzed to illustrate the findings of the article. Based on the simulation study, some possible good interval estimators have been recommended for the practitioners.     

Labour mobility and regional disparities: the role of female labour participation

Unemployment rates, as well as income per capita, differ vastly across the regions of Europe. Labour mobility can play a role in resolving regional disparities. This paper focuses on the questions of why labour mobility is low in the EU and how it is possible that it remains low. We explore whether changes in male and female labour participation act as an important alternative adjustment mechanism. We answer this question in the affirmative. We argue that female labour participation is very important in adjusting to regional disparities.