• 제목/요약/키워드: Chi-squared Test

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The Rao-Robson Chi-Squared Test for Multivariate Structure

  • Park, Cheol-Yong
    • Journal of the Korean Data and Information Science Society
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    • v.14 no.4
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    • pp.1013-1021
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    • 2003
  • Huffer and Park (2002) proposed a chi-squared test for multivariate structure. Their test detects the deviation of data from mutual independence or multivariate normality. We will compute the Rao-Robson chi-squared version of the test, which is easy to apply in practice since it has a limiting chi-squared distribution. We will provide a self-contained argument that it has a limiting chi-squared distribution. We study the accuracy in finite samples of the limiting distribution. We finally compare the power of our test with those of other popular normality tests in an application to a real data.

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A Note on the Simple Chi-Squared Test of Multivariate Normality

  • Park, Cheol-Yong
    • Journal of the Korean Data and Information Science Society
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    • v.15 no.2
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    • pp.423-430
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    • 2004
  • We provide the exact form of a Rao-Robson version of the chi-squared test of multivariate normality suggested by Park(2001). This test is easy to apply in practice since it is easily computed and has a limiting chi-squared distribution under multivariate normality. A self-contained formal argument is provided that it has the limiting chi-squared distribution. A simulation study is provided to study the accuracy, in finite samples, of the limiting distribution. Finally, a simulation study in a nonnormal distribution is conducted in order to compare the power of our test with those of other popular normality tests.

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A Simple Chi-squared Test of Multivariate Normality Based on the Spherical Data

  • Park, Cheolyong
    • Communications for Statistical Applications and Methods
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    • v.8 no.1
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    • pp.117-126
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    • 2001
  • We provide a simple chi-squared test of multivariate normality based on rectangular cells on the spherical data. This test is simple since it is a direct extension of the univariate chi-squared test to multivariate case and the expected cell counts are easily computed. We derive the limiting distribution of the chi-squared statistic via the conditional limit theorems. We study the accuracy in finite samples of the limiting distribution and then compare the poser of our test with those of other popular tests in an application to a real data.

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A Simple Chi-Squared Test of Spherical Symmetry

  • Park, Cheol-Yong
    • Journal of the Korean Data and Information Science Society
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    • v.16 no.2
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    • pp.227-236
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    • 2005
  • A chi-squared test of spherical symmetry is suggested. This test is easy to apply in practice since it is easy to compute and has a limiting chi-squared distribution under spherical symmetry. The result of Park(1998) can be used to show that it has the limiting chi-squared distribution. A simulation study is conducted to study the accuracy, in finite samples, of the limiting distribution. Finally, a simulation study that compares the power of our test with those of other tests of spherical symmetry is performed.

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The Chi-squared Test of Independence for a Multi-way Contingency Table wish All Margins Fixed

  • Park, Cheolyong
    • Journal of the Korean Statistical Society
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    • v.27 no.2
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    • pp.197-203
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    • 1998
  • To test the hypothesis of complete or total independence for a multi-way contingency table, the Pearson chi-squared test statistic is usually employed under Poisson or multinomial models. It is well known that, under the hypothesis, this statistic follows an asymptotic chi-squared distribution. We consider the case where all marginal sums of the contingency table are fixed. Using conditional limit theorems, we show that the chi-squared test statistic has the same limiting distribution for this case.

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The Eccentric Properties of the Chi-Squared Test with Yates' Continuity Correction in Extremely Unbalanced 2×2 Contingency Table

  • Kang, Seung-Ho;Kwon, Tae-Hyuk
    • The Korean Journal of Applied Statistics
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    • v.23 no.4
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    • pp.777-781
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    • 2010
  • Yates' continuity correction of the chi-squared test for testing the homogeneity of two binomial proportions in $2{\times}2$ contingency tables is developed to lower the value of the test statistic slightly. The effect of continuity correction is expected to decrease as the sample size increases. However, in extremely unbalanced $2{\times}2$ contingency tables, we find some cases where the effect of continuity correction is eccentric and is larger than expected. In such cases, we conclude that the chi-squared test with continuity correction should not be employed as a test statistic in both asymptotic tests and exact tests.

Notes on the Goodness-of-Fit Tests for the Ordinal Response Model

  • Jeong, Kwang-Mo;Lee, Hyun-Yung
    • The Korean Journal of Applied Statistics
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    • v.23 no.6
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    • pp.1057-1065
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    • 2010
  • In this paper we discuss some cautionary notes in using the Pearson chi-squared test statistic for the goodness-of-fit of the ordinal response model. If a model includes continuous type explanatory variables, the resulting table from the t of a model is not a regular one in the sense that the cell boundaries are not fixed but randomly determined by some other criteria. The chi-squared statistic from this kind of table does not have a limiting chi-square distribution in general and we need to be very cautious of the use of a chi-squared type goodness-of-t test. We also study the limiting distribution of the chi-squared type statistic for testing the goodness-of-t of cumulative logit models with ordinal responses. The regularity conditions necessary to the limiting distribution will be reformulated in the framework of the cumulative logit model by modifying those of Moore and Spruill (1975). Due to the complex limiting distribution, a parametric bootstrap testing procedure is a good alternative and we explained the suggested method through a practical example of an ordinal response dataset.

Effect of Bias on the Pearson Chi-squared Test for Two Population Homogeneity Test

  • Heo, Sunyeong
    • Journal of Integrative Natural Science
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    • v.5 no.4
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    • pp.241-245
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    • 2012
  • Categorical data collected based on complex sample design is not proper for the standard Pearson multinomial-based chi-squared test because the observations are not independent and identically distributed. This study investigates effects of bias of point estimator of population proportion and its variance estimator to the standard Pearson chi-squared test statistics when the sample is collected based on complex sampling scheme. This study examines the effect under two population homogeneity test. The standard Pearson test statistic can be partitioned into two parts; the first part is the weighted sum of ${\chi}^2_1$ with eigenvalues of design matrix as their weights, and the additional second part which is added due to the biases of the point estimator and its variance estimator. Our empirical analysis shows that even though the bias of point estimator is small, Pearson test statistic is very much inflated due to underestimate the variance of point estimator. In the connection of design-based variance estimator and its design matrix, the bigger the average of eigenvalues of design matrix is, the larger relative size of which the first component part to Pearson test statistic is taking.

A Simple Nonparametric Test of Complete Independence

  • Park, Cheol-Yong
    • Communications for Statistical Applications and Methods
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    • v.5 no.2
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    • pp.411-416
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    • 1998
  • A simple nonparametric test of complete or total independence is suggested for continuous multivariate distributions. This procedure first discretizes the original variables based on their order statistics, and then tests the hypothesis of complete independence for the resulting contingency table. Under the hypothesis of independence, the chi-squared test statistic has an asymptotic chi-squared distribution. We present a simulation study to illustrate the accuracy in finite samples of the limiting distribution of the test statistic. We compare our method to another nonparametric test of complete independence via a simulation study. Finally, we apply our method to the residuals from a real data set.

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A Test for Multivariate Normality Focused on Elliptical Symmetry Using Mahalanobis Distances

  • Park, Cheol-Yong
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.4
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    • pp.1191-1200
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    • 2006
  • A chi-squared test of multivariate normality is suggested which is mainly focused on detecting deviations from elliptical symmetry. This test uses Mahalanobis distances of observations to have some power for deviations from multivariate normality. We derive the limiting distribution of the test statistic by a conditional limit theorem. A simulation study is conducted to study the accuracy of the limiting distribution in finite samples. Finally, we compare the power of our method with those of other popular tests of multivariate normality under two non-normal distributions.

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