Results 261 to 270 of about 8,439,715 (292)

Score test for testing zero-inflated Poisson regression against zero-inflated generalized Poisson alternatives

Journal of Applied Statistics, 2013
In several cases, count data often have excessive number of zero outcomes. This zero-inflated phenomenon is a specific cause of overdispersion, and zero-inflated Poisson regression model (ZIP) has been proposed for accommodating zero-inflated data. However, if the data continue to suggest additional overdispersion, zero-inflated negative binomial (ZINB)
Hossein Zamani, Noriszura Ismail
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Score tests for zero-inflated generalized Poisson mixed regression models

Computational Statistics & Data Analysis, 2009
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Feng-Chang Xie, Bo-Cheng Wei, Jin-Guan Lin   +2 more
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Score Test for Zero Inflated Generalized Poisson Regression Model

Communications in Statistics - Theory and Methods, 2005
In certain applications involving count data, it is sometimes found that zeros are observed with a frequency significantly higher (lower) than predicted by the assumed model. Examples of such applications are cited in the literature from engineering, manufacturing, economics, public health, epidemiology, psychology, sociology, political science ...
Pushpa Lata Gupta, Ramesh C. Gupta, Ram C. Tripathi   +2 more
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Score Tests for Extra-Zero Models in Zero-Inflated Negative Binomial Models

Communications in Statistics - Simulation and Computation, 2008
When overdispersion is present in count data, a negative binomial (NB) model is commonly used in place of the standard Poisson model. However, the model is sometimes not adequate because of the occurrence of excess zeros and a zero-inflated negative binomial (ZNB) model may be more appropriate.
N. Jansakul, John P. Hinde
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Score tests for heterogeneity and overdispersion in zero‐inflated Poisson and binomial regression models

Canadian Journal of Statistics, 2002
AbstractHall (2000) has described zero‐inflated Poisson and binomial regression models that include random effects to account for excess zeros and additional sources of heterogeneity in the data. The authors of the present paper propose a general score test for the null hypothesis that variance components associated with these random effects are zero ...
Hall, Daniel B., Berenhaut, Kenneth S.
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Inflated Test Score Gains: Is the Problem Old Norms or Teaching the Test?

Educational Measurement: Issues and Practice, 1990
What explanations have been provided for spurious test score gains? Are states and districts narrowing the curriculum and teaching the test? What effect does teaching the test have on the norms themselves? What alternatives must be sought to protect the integrity of instruction and the validity of scores?
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Improvement in National Test arithmetic scores at Key Stage 1: Grade inflation or better achievement?

British Educational Research Journal, 2008
The aim of the National Numeracy Strategy is to raise standards in numeracy. Strong evidence for its success has, however, been lacking: most of the available data come from performance on National Test assessments administered in schools or from Ofsted reports, and is vulnerable to suggestions of bias.
Meadows, S.A.C, Herrick, D.R.M, Witt, M.N, the ALSPAC Study, Team   +3 more
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Outlier removal, sum scores, and the inflation of the type I error rate in independent samples t tests: The power of alternatives and recommendations.

Psychological Methods, 2014
In psychology, outliers are often excluded before running an independent samples t test, and data are often nonnormal because of the use of sum scores based on tests and questionnaires. This article concerns the handling of outliers in the context of independent samples t tests applied to nonnormal sum scores.
Marjan Bakker, Jelte M. Wicherts
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Score Tests for Overdispersion in Marginalized Zero‐Inflated Poisson Regression Based on Marginalized Zero‐Inflated Generalized Poisson Model

Statistical Analysis and Data Mining: An ASA Data Science Journal
ABSTRACT A marginalized zero‐inflated Poisson (MZIP) model has been developed to allow practitioners to make direct inferences about the marginal mean of count data while accounting for the excess zeros in the data. Overdispersion is a well‐documented issue in models that include the Poisson distribution, such as the traditional zero ...
Yuhe Wang, Yuecai Han
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sj-pdf-1-smm-10.1177_0962280220937324 - Supplemental material for A robust score test of homogeneity for zero-inflated count data

2020
Supplemental material, sj-pdf-1-smm-10.1177_0962280220937324 for A robust score test of homogeneity for zero-inflated count data by Wei-Wen Hsu, David Todem, Nadeesha R Mawella, KyungMann Kim and Richard R Rosenkranz in Statistical Methods in Medical ...
Hsu, Wei-Wen, Todem, David, Nadeesha R Mawella, KyungMann Kim, Rosenkranz, Richard R   +4 more
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