In medical and social science research, reliability of testing methods measured through inter‐ and intraobserver agreement is critical in disease diagnosis. Often comparison of agreement across ...multiple testing methods is sought in situations where testing is carried out on the same experimental units rendering the outcomes to be correlated. In this article, we first developed a Bayesian method for comparing dependent agreement measures under a grouped data setting. Simulation studies showed that the proposed methodology outperforms the competing methods in terms of power, while maintaining a decent type I error rate. We further developed a Bayesian joint model for comparing dependent agreement measures adjusting for subject and rater‐level heterogeneity. Simulation studies indicate that our model outperforms a competing method that is used in this context. The developed methodology was implemented on a key measure on a dichotomous rating scale from a study with six raters evaluating three classification methods for chest radiographs for pneumoconiosis developed by the International Labor Office.
•Analysis of offender fingerprints from evidence types in crimes against property.•Offender fingerprints are frequently seen in common entry points such as doors.•Porous and non-porous fingerprints ...are found to be similar in both property settings.•Offender fingerprints are generally located on the forward portion of a vehicle.•Vehicular body and glass component show equal likelihood of offender fingerprints.
The Forensic Institute of the Republic of North Macedonia data set of 1,982 offender fingerprint identifications contributing to a conviction for crimes against property, was evaluated and analysed using contingency table statistical analysis techniques, chi-square test, fisher’s exact test and post hoc analysis. The data set was based on the forensic and court information available from 2005 to 2015 and pertained to the location, property type and evidence type. Interpretation of the data identified glass components, doors, windows, points of entry, cardboard and other packaging to be the most likely areas for locating offender fingerprints in non-residential and residential properties. In vehicle-based crimes, the front area (both left- and right-hand side) was the most likely to yield offender fingerprints.
This study reinforced the types of evidential items at property based crime scenes yielding offender fingerprints. In addition, the study seeks to provide recommendations for future data collection to enhance the data analysis and interpretation.
Test of homogeneity of covariances (or homoscedasticity) among several groups has many applications in statistical analysis. In the context of incomplete data analysis, tests of homoscedasticity ...among groups of cases with identical missing data patterns have been proposed to test whether data are missing completely at random (MCAR). These tests of MCAR require large sample sizes
n
and/or large group sample sizes
n
i
, and they usually fail when applied to nonnormal data. Hawkins (Technometrics 23:105–110,
1981
) proposed a test of multivariate normality and homoscedasticity that is an exact test for complete data when
n
i
are small. This paper proposes a modification of this test for complete data to improve its performance, and extends its application to test of homoscedasticity and MCAR when data are multivariate normal and incomplete. Moreover, it is shown that the statistic used in the Hawkins test in conjunction with a nonparametric
k
-sample test can be used to obtain a nonparametric test of homoscedasticity that works well for both normal and nonnormal data. It is explained how a combination of the proposed normal-theory Hawkins test and the nonparametric test can be employed to test for homoscedasticity, MCAR, and multivariate normality. Simulation studies show that the newly proposed tests generally outperform their existing competitors in terms of Type I error rejection rates. Also, a power study of the proposed tests indicates good power. The proposed methods use appropriate missing data imputations to impute missing data. Methods of multiple imputation are described and one of the methods is employed to confirm the result of our single imputation methods. Examples are provided where multiple imputation enables one to identify a group or groups whose covariance matrices differ from the majority of other groups.
In ophthalmologic or otolaryngologic study, each subject may contribute paired organs measurements to the analysis. A number of statistical methods have been proposed on bilateral correlated data. In ...practice, it is important to detect confounding effect by treatment interaction, since ignoring confounding effect may lead to unreliable conclusion. Therefore, stratified data analysis can be considered to adjust the effect of confounder on statistical inference. In this article, we investigate and derive three test procedures for testing homogeneity of difference of two proportions for stratified correlated paired binary data in the basis of equal correlation model assumption. The performance of proposed test procedures is examined through Monte Carlo simulation. The simulation results show that the Score test is usually robust on type I error control with high power, and therefore is recommended among the three methods. One example from otolaryngologic study is given to illustrate the three test procedures.
This article analyzes the effectiveness of various beta coefficient modifications in forecasting on the Russian stock market. Objective: To test the hypothesis of the superiority of modified beta ...coefficients in forecast accuracy. Methods: Calculating and comparing the stock returns of ten companies that play a key role in the Russian economy based on three beta coefficient modifications: classic, Monkhouse, and two beta. The criteria were used for verifying sample homogeneity in order to test the hypothesis that modified beta coefficients produce more accurate forecasting. Results: The analysis showed that, in most cases, none of the three models obtained relevant results for the Russian companies. None of the modifications tested can be recognized with high confidence as more accurate than traditional beta coefficients. Conclusions: In the contemporary Russian stock market, the CAPM does not allow one to produce satisfactory forecasts on stock returns.
The empirical likelihood ratio test (ELRT) statistic is constructed for testing the homogeneity of several nonparametric populations in the presence of some auxiliary information. It is shown—under ...some regularity conditions and under the null hypothesis that all distribution functions of the populations are equal—that the asymptotic distribution of the ELRT is a chi-squared distribution. The proposed ELRT could be more powerful than the Kruskal–Wallis test, as extra information can be efficiently employed by ELRT. The advantage of ELRT over T&P (2006) is that researchers do not need to select approximately normal statistics for inter-group comparisons, and ELRT is more suitable for the multi-population consistency test with a small sample size.
Count data with excess zeros encountered in many applications often exhibit extra variation. Therefore, zero-inflated Poisson (ZIP) model may fail to fit such data. In this paper, a zero-inflated ...double Poisson model (ZIDP), which is generalization of the ZIP model, is studied and the score tests for the significance of dispersion and zero-inflation in ZIDP model are developed. Meanwhile, this work also develops homogeneous tests for dispersion and/or zero-inflation parameter, and corresponding score test statistics are obtained. One numerical example is given to illustrate our methodology and the properties of score test statistics are investigated through Monte Carlo simulations.
패널 마코프 체인의 구조를 소개하고 우도함수를 도출하여 전이확률을 추정하였다. 패널 마코프 체인의 전이확률의 동질성 검정통계량으로 LR 통계량을 제안하고 그 극한분포를 제시하였다. 동질성 검정통계량의 극한분포를 패널의 수를 달리하여 모의실험하였으며 패널의 수가 50개 이상인 경우 동질성 검정통계량의 분포가 카이제곱분포를 따르는 것을 확인하였다. 정상적인 ...경우 검정통계량이 우수한 검정력을 가지는 것을 보였고, 확률보행과정과 같이 비정상적인 경우 검정통계량이 전이확률의 비동질성을 잘 반영하는 것을 확인하였다.
The test of transition probabilities in panel Markov chains are introduced. We deal with the hypotheses whether panel Markov chains have the same transition probabilities or not for all times. We suggest a LR test statistic for the test and its limit distribution is derived. We perform a simulation study to examine the limit distribution of test statistics when the number of the individuals are large.
In this paper, several diagnostics measures are proposed based on case-deletion model for log-Birnbaum–Saunders regression models (LBSRM), which might be a necessary supplement of the recent work ...presented by Galea et al. 2004. Influence diagnostics in log-Birnbaum–Saunders regression models. J. Appl. Statist. 31, 1049–1064 who studied the influence diagnostics for LBSRM mainly based on the local influence analysis. It is shown that the case-deletion model is equivalent to the mean-shift outlier model in LBSRM and an outlier test is presented based on mean-shift outlier model. Furthermore, we investigate a test of homogeneity for shape parameter in LBSRM, which is a problem mentioned by both Rieck and Nedelman 1991. A log-linear model for the Birnbaum–Saunders distribution. Technometrics 33, 51–60 and Galea et al. 2004. Influence diagnostics in log-Birnbaum–Saunders regression models. J. Appl. Statist. 31, 1049–1064. We obtain the likelihood ratio and score statistics for such test. Finally, a numerical example is given to illustrate our methodology and the properties of likelihood ratio and score statistics are investigated through Monte Carlo simulations.
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