• 제목/요약/키워드: Contingency table

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Bayesian test of homogenity in small areas: A discretization approach

  • Kim, Min Sup;Nandram, Balgobin;Kim, Dal Ho
    • Journal of the Korean Data and Information Science Society
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    • 제28권6호
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    • pp.1547-1555
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    • 2017
  • This paper studies Bayesian test of homogeneity in contingency tables made by discretizing a continuous variable. Sometimes when we are considering events of interest in small area setup, we can think of discretization approaches about the continuous variable. If we properly discretize the continuous variable, we can find invisible relationships between areas (groups) and a continuous variable of interest. The proper discretization of the continuous variable can support the alternative hypothesis of the homogeneity test in contingency tables even if the null hypothesis was not rejected through k-sample tests involving one-way ANOVA. In other words, the proportions of variables with a particular level can vary from group to group by the discretization. If we discretize the the continuous variable, it can be treated as an analysis of the contingency table. In this case, the chi-squared test is the most commonly employed method. However, further discretization gives rise to more cells in the table. As a result, the count in the cells becomes smaller and the accuracy of the test becomes lower. To prevent this, we can consider the Bayesian approach and apply it to the setup of the homogeneity test.

Detection of Random Effects in a Random Effects Model of a One-way Layout Contingency Table

  • Kim, Byung-Soo
    • Journal of the Korean Statistical Society
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    • 제13권1호
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    • pp.1-19
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    • 1984
  • A random effects model of a one-way layout contingency table is developed using a Dirichlet-multinomial distribution. A test statistic, say $T_k$, is suggested for detecting Dirichlet-multinomial departure from a multinomial distribution. It is shown that the $T_k$ test is asymptotically superior to the classical chi-square test based on the asymptotic relative efficiency. This superiority is further evidenced by a Monte Carlo simulation.

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A Bayesian uncertainty analysis for nonignorable nonresponse in two-way contingency table

  • Woo, Namkyo;Kim, Dal Ho
    • Journal of the Korean Data and Information Science Society
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    • 제26권6호
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    • pp.1547-1555
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    • 2015
  • We study the problem of nonignorable nonresponse in a two-way contingency table and there may be one or two missing categories. We describe a nonignorable nonresponse model for the analysis of two-way categorical table. One approach to analyze these data is to construct several tables (one complete and the others incomplete). There are nonidentifiable parameters in incomplete tables. We describe a hierarchical Bayesian model to analyze two-way categorical data. We use a nonignorable nonresponse model with Bayesian uncertainty analysis by placing priors in nonidentifiable parameters instead of a sensitivity analysis for nonidentifiable parameters. To reduce the effects of nonidentifiable parameters, we project the parameters to a lower dimensional space and we allow the reduced set of parameters to share a common distribution. We use the griddy Gibbs sampler to fit our models and compute DIC and BPP for model diagnostics. We illustrate our method using data from NHANES III data to obtain the finite population proportions.

Correlation plot for a contingency table

  • Hong, Chong Sun;Oh, Tae Gyu
    • Communications for Statistical Applications and Methods
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    • 제28권3호
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    • pp.295-305
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    • 2021
  • Most graphical representation methods for two-dimensional contingency tables are based on the frequencies, probabilities, association measures, and goodness-of-fit statistics. In this work, a method is proposed to represent the correlation coefficients for each of the two selected levels of the row and column variables. Using the correlation coefficients, one can obtain the vector-matrix that represents the angle corresponding to each cell. Thus, these vectors are represented as a unit circle with angles. This is called a CC plot, which is a correlation plot for a contingency table. When the CC plot is used with other graphical methods as well as statistical models, more advanced analyses including the relationship among the cells of the row or column variables could be derived.

Contour Method and Collapsibility Criteria for $2{\times}3{\times}K$ Contingency Tables

  • Hong, C.S.;Son, B.U.;Park, J.Y.
    • Journal of the Korean Data and Information Science Society
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    • 제15권4호
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    • pp.717-729
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    • 2004
  • The contour method which was originally designed for $2{\times}2{\times}2$ contingency table is studied for $2{\times}2{\times}K$ and $2{\times}3{\times}K$ tables. Whereas a contour plot for a $2{\times}2{\times}K$ table is represented on unit squared two dimensional plane, a contour plot of a $2{\times}3{\times}K$ table can be expressed with a regular hexahedron on three dimensional space. Based on contour plots for categorical data fitted to all possible three dimensional log-linear models, one might identify whether $2{\times}2{\times}k$ or $2{\times}3{\times}K$ tables are collapsible over the third variable.

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단계별로 얻어진 이차원 분할표의 모수 추정을 위한 정확최대우도추정법과 단계별추출추정법의 비교 (Comparison of Step-Wise and Exact Maximum Likelihood Estimations on Cell Probabilities of Contingency Table)

  • 이상은;강기훈;정석오;신기일
    • Communications for Statistical Applications and Methods
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    • 제17권1호
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    • pp.67-77
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    • 2010
  • 단계별로 얻어진 $I{\times}J$ 이차원 범주형 자료에서 분할표 일부의 칸에서 도수가 붕괴(collapse)된 상태로 조사가 이루어진 것을 단계별추출(step-wise sampling)이라 한다. 단계별추출로 얻어진 자료를 분석할 경우 단계별추출법을 사용하여 분석하면 분석의 효과를 얻을 수 있다. 본 논문에서는 단계별추출법 중에서 최대우도추정법을 이용하여 얻어진 정확최대우도추정량(exact maximum likelihood estimator)과 단계별추출최대우도추정량을 연구하였다. 또한 MSE와 편향(bias)을 기준으로 모의실험을 통하여 두 추정법을 비교하였다.

mXm 분할표에서의 합치도 H (Measure of Agreement H in mXm Contingency Table)

  • 김진곤;박미희;박용규
    • Communications for Statistical Applications and Methods
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    • 제16권5호
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    • pp.753-762
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    • 2009
  • 평정자간 일치 정도를 나타내는 측도로 주로 사용되는 k의 문제점을 해결하기 위해 박미희와 박용규(2007)는 $2{\times}2$ 분할표에서 새로운 합치도 H를 제안하였다. 본 연구에서는 이를 확장하여 $m{\times}m$ 분할표에 대한 합치도 H와 그 분산을 구한다. 또한 k의 역설과 주변분포와의 관계를 증명하고, $3{\times}3$ 분할표 예제를 이용하여 기존의 합치도들과 비교한다.

Bayesian Test of Quasi-Independence in a Sparse Two-Way Contingency Table

  • Kwak, Sang-Gyu;Kim, Dal-Ho
    • Communications for Statistical Applications and Methods
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    • 제19권3호
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    • pp.495-500
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    • 2012
  • We consider a Bayesian test of independence in a two-way contingency table that has some zero cells. To do this, we take a three-stage hierarchical Bayesian model under each hypothesis. For prior, we use Dirichlet density to model the marginal cell and each cell probabilities. Our method does not require complicated computation such as a Metropolis-Hastings algorithm to draw samples from each posterior density of parameters. We draw samples using a Gibbs sampler with a grid method. For complicated posterior formulas, we apply the Monte-Carlo integration and the sampling important resampling algorithm. We compare the values of the Bayes factor with the results of a chi-square test and the likelihood ratio test.

반복비율적합에 의한 다차원 분할표의 결측칸값 추정 (Estimating Missing Cells in Contingency Table with IPE)

  • 최현집;신상준
    • 응용통계연구
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    • 제13권1호
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    • pp.197-206
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    • 2000
  • 반복비율적합 방법을 확장하여 준독립성모형하에서 불완전한 다차원 분할표에 포함된 결측칸의 최우추정값을 얻기 위한 추정방법을 제안하였다. 제안된 방법은 주변합이 영이 아닌 모든 불완전한 분할표에 적용할 수 있으며 주어진 준로그선형모형의 구조를 해치지 않는다. 또한 결측칸의 위치와 수에 영향을 받지 않고 항상 수렴한다는 것을 확인하였다.

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