• Title/Summary/Keyword: Contingency tables

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Identification of Multiple Outlying Cells in Multi-way Tables

  • Lee, Jong Cheol;Hong, Chong Sun
    • Communications for Statistical Applications and Methods
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    • v.7 no.3
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    • pp.687-698
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    • 2000
  • An identification method is proposed in order to detect more than one outlying cells in multi-way contingency tables. The iterative proportional fitting method is applied to get expected values of several suspected outlying cells. Since the proposed method uses minimal sufficient statistics under quasi log-linear models, expected counts of outlying cells could be estimated under any hierarchical log-linear models. This method is an extension of the backwards-stepping method of Simonoff(1988) and requires les iteration to identify outlying cells.

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Generating Multidimensional Random Tables (다차원 임의 분할표 생성)

  • Choi, Hyun-Jip
    • The Korean Journal of Applied Statistics
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    • v.19 no.3
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    • pp.545-554
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    • 2006
  • We suggest a method for generating multidimensional random tables based on the log-linear models. A linear combination approach by Lee(1997) is applied to get the joint distribution with the well known Pearson chi-squared statistics. We can generate completely associated joint distributions which have the fixed association among three variables by using the suggested method. Therefore the method can be extended to more higher dimension than the three dimensional tables.

Correlation plot for a contingency table

  • Hong, Chong Sun;Oh, Tae Gyu
    • Communications for Statistical Applications and Methods
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    • v.28 no.3
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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.

Logit Confidence Intervals Using Pseudo-Bayes Estimators for the Common Odds Ratio in 2 X 2 X K Contingency Tables

  • Kim, Donguk;Chun, Eunhee
    • Communications for Statistical Applications and Methods
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    • v.10 no.2
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    • pp.479-496
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    • 2003
  • We investigate logit confidence intervals for the odds ratio based on the delta method. These intervals are constructed using pseudo-Bayes estimators. The Gart method and Agresti method smooth the observed counts toward the model of equiprobability and independence, respectively. We obtain better coverage probability by smoothing the observed counts toward the pseudo-Bayes estimators in 2$\times$2 table. We also improve legit confidence intervals in 2$\times$2$\times$K tables by generalizing these ideas. Utilizing pseudo-Bayes estimators, we obtain better coverage probability by smoothing the observed counts toward the conditional independence model, no three-factor interaction model and saturated model in 2$\times$2$\times$K tables.

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

  • Lee, Sang-Eun;Kang, Kee-Hoon;Jeung, Seok-O;Shin, Key-Il
    • Communications for Statistical Applications and Methods
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    • v.17 no.1
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    • pp.67-77
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    • 2010
  • In multinomial scheme with step-wise sampling, maximum likelihood estimates of multinomial probabilities are improved when some frequencies are merged. In this study, for cell probabilities in a I by J independent contingency tables, exact MLE and step-wise estimation methods are applied and the results are compared using MSE and Bias.

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

  • Kim, Jin-Gon;Park, Mi-Hee;Park, Yong-Gyu
    • Communications for Statistical Applications and Methods
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    • v.16 no.5
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    • pp.753-762
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    • 2009
  • A measure of agreement H in$2{\times}2$ contingency table was proposed by Park and Park (2007) to resolve the two paradoxes of k. In this study, we generalize H to where the number of categories is greater than two and derive its asymptotic large-sample variance. We also explain the relationships between k's paradoxes and marginal distributions. Using some examples of $3{\times}3$ contingency tables, the behaviors of H and other measures of agreement are compared.

Design of a Fast Algorithm for Computing Contingency Tables that are Used to Construct Epistasis Networks of SNPs (단일염기다형성 상위성 네트워크를 구성하기 위한 분할표를 생성하는 빠른 알고리즘의 설계)

  • Wang, Sehee;Wee, Kyubum
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2016.07a
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    • pp.21-24
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    • 2016
  • 전장유전체 연관성 연구에서 상위성 탐색은 많은 단일염기다형성 수로 인해 계산이 어렵기 때문에 네트워크에서의 탐색을 이용한 방법이 사용되고 있다. 그러나 전장유전체 연관성 연구에서 단일염기다형성들의 상위성 네트워크의 구성 역시 큰 계산 비용을 필요로 한다. 본 논문에서는 단일염기다형성과 표현형의 상호정보량을 이용한 네트워크를 구성하는데 드는 시간을 줄이는 알고리즘을 제안한다. 또한 표본 크기별로 계산 시간을 실험해 보았으며, 기존의 방법과 비교해 실행 속도가 향상됨을 보였다.

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

  • 최현집;신상준
    • The Korean Journal of Applied Statistics
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    • v.13 no.1
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    • pp.197-206
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    • 2000
  • For estimating missing cells in contingency table, we suggest an iterative method which extends IPF (Iterative Proportional Fitting) method. The suggested m~thod is not restricted by the number and the location of missing cells, and does not distort the given quasi-independency.

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A Study on Cell Influences to Chi-square Statistic in Contingency Tables

  • Kim, Hong-Gie
    • Communications for Statistical Applications and Methods
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    • v.5 no.1
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    • pp.35-42
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    • 1998
  • Once a contingency table is constructed, the first interest will be the hypotheses of either homogeneity or independence depending on the sampling scheme. The most widely used test statistic in practice is the classical Pearson's $\chi^2$ statistic. When the null hypothesis is rejected, another natural interest becomes which cell contributed to the rejection of the null hypothesis more than others. For this purpose, so called cell $\chi^2$ components are investigated. In this paper, the influence function of a cell to the $\chi^2$ statistic is derived, which can be used for the same purpose. This function measures the effect of each cell to the $\chi$$^2$ statistic. A numerical example is given to demonstrate the role of the new function.

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Influence Functions on $ {\chi}^2$ Statistic in Contingency Tables

  • Honggie Kim;Hee-Sook Lee
    • Communications for Statistical Applications and Methods
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    • v.3 no.2
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    • pp.69-76
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    • 1996
  • In a two-way contingency table, the analyst is most interested in the hypotheses of either homogeneity or independence. For testing this as a null hypothesis, Pearson's ${\chi}^2$ statistic is most commonly used in practice. Once the null Hypothesis is rejected, he will further search forcells which caused the rejection of the null hypothesis. For this purpose, so called cell${\chi}^2$ components are used. In this paper, we derive the influence function of an obsevation to the ${\chi}^2$ statistic, with which cells with high influence can be identified.

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