Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Bias (28)
- Monte Carlo simulation (27)
- Bootstrap (26)
- Simulation (26)
- Power (23)
-
- Confidence interval (22)
- Mean squared error (20)
- Type I error (20)
- Effect size (19)
- Robustness (19)
- Monte Carlo (18)
- Sample size (18)
- Multicollinearity (17)
- Permutation test (17)
- Maximum likelihood estimation (16)
- Missing data (16)
- Reliability (14)
- Confidence intervals (13)
- Efficiency (13)
- Heteroscedasticity (13)
- Logistic regression (13)
- SPSS (13)
- P-value (12)
- Simple random sampling (12)
- Estimation (11)
- Nonnormality (11)
- Regression (11)
- ANOVA (10)
- Bayesian estimation (10)
- Loss functions (10)
- Publication Year
- Publication
- Publication Type
- File Type
Articles 1081 - 1110 of 1116
Full-Text Articles in Physical Sciences and Mathematics
On The Estimation Of Binomial Success Probability With Zero Occurrence In Sample, Mehdi Razzaghi
On The Estimation Of Binomial Success Probability With Zero Occurrence In Sample, Mehdi Razzaghi
Journal of Modern Applied Statistical Methods
The problem of estimating the probability of a rare event when the sample shows no incidence of the event is considered. Several methodologies based on various statistical techniques are described and their relative performances are investigated. A decision theoretic approach for estimation of response probability when the sample contains zero responses is examined in depth. The properties of each method are discussed and an example from teratology is used to provide illustration and to demonstrate the results.
Null Distribution Of The Likelihood Ratio Statistic For Feed-Forward Neural Networks, Douglas Landsittel, Harshinder Singh, Vincent C. Arena, Stewart J. Anderson
Null Distribution Of The Likelihood Ratio Statistic For Feed-Forward Neural Networks, Douglas Landsittel, Harshinder Singh, Vincent C. Arena, Stewart J. Anderson
Journal of Modern Applied Statistical Methods
Despite recent publications exploring model complexity with modern regression methods, their dimensionality is rarely quantified in practice and the distributions of related test statistics are not well characterized. Through a simulation study, we describe the null distribution of the likelihood ratio statistic for several different feed-forward neural network models.
A Simulation Study Of The Impact Of Forecast Recovery For Control Charts Applied To Arma Processes, John N. Dyer, B. Michael Adams, Michael D. Conerly
A Simulation Study Of The Impact Of Forecast Recovery For Control Charts Applied To Arma Processes, John N. Dyer, B. Michael Adams, Michael D. Conerly
Journal of Modern Applied Statistical Methods
Forecast-based schemes are often used to monitor autocorrelated processes, but the resulting forecast recovery has a significant effect on the performance of control charts. This article describes forecast recovery for autocorrelated processes, and the resulting simulation study is used to explain the performance of control charts applied to forecast errors.
Accounting For Non-Independent Observations In 2×2 Tables, With Application To Correcting For Family Clustering In Exposure-Risk Relationship Studies, Leslie A. Kalsih, Katherine A. Riester, Stuart J. Pocock
Accounting For Non-Independent Observations In 2×2 Tables, With Application To Correcting For Family Clustering In Exposure-Risk Relationship Studies, Leslie A. Kalsih, Katherine A. Riester, Stuart J. Pocock
Journal of Modern Applied Statistical Methods
Participants in epidemiologic studies may not represent statistically independent observations. We consider modifications to conventional analyses of 2×2 tables, including Fisher’s exact test and confidence intervals, to account for correlated observations in this setting. An example is provided, assessing the robustness of conclusions from a published analysis.
Combining Quantum Mechanical Calculations And A Χ^2 Fit In A Potential Energy Function For The Co_2 + O^+ Reaction, Ellen F. Sawilowsky
Combining Quantum Mechanical Calculations And A Χ^2 Fit In A Potential Energy Function For The Co_2 + O^+ Reaction, Ellen F. Sawilowsky
Journal of Modern Applied Statistical Methods
In order to compute a highly accurate statistical rate constant for the CO2 + O+ reaction, it is necessary to first calculate the potential energy of the system at many different geometric configurations. Quantum mechanical calculations are very time-consuming, making it difficult to obtain a sufficient number to allow for accurate interpolation. The number of quantum mechanical calculations required can be significantly reduced by using known relations in classical physics to calculate energy for configurations where the oxygen is relatively far from the CO2. A chi-squared fit to quantum mechanical points is obtained for these configurations, and the resulting …
Type I Error Rates For Rank-Based Tests Of Homogeneity Of Slopes, Alan J. Klockars, Tim P. Moses
Type I Error Rates For Rank-Based Tests Of Homogeneity Of Slopes, Alan J. Klockars, Tim P. Moses
Journal of Modern Applied Statistical Methods
The purpose of this study was to explicate two issues concerning the standard and rank based test of homogeneity of slopes. Two alternative ranking methods intended to address nonnormality and additive treatment effect patterns were developed and compared in terms of their ability to control Type I error. The results replicated previous findings of inflated Type I error rates with leptokurtic curves and with rank based tests with some patterns of additive treatment effects. The new nonparametric procedures generally control Type I error although they were slightly inflated with skewed distributions.
Exploration Of Distributions Of Ratio Of Partial Sum Of Sample Eigenvalues When All Population Eigenvalues Are The Same, Moonseong Heo
Exploration Of Distributions Of Ratio Of Partial Sum Of Sample Eigenvalues When All Population Eigenvalues Are The Same, Moonseong Heo
Journal of Modern Applied Statistical Methods
This paper explores empirically the first two moments of ratio of the partial sum of the first two sample eigenvalues to the sum of all eigenvalues when the population eigenvalues of a covariance matrix are all the same. Estimation of the first two moments can be practically crucial in assessing non-randomness of observed patterns on planar graphical displays based on lower rank approximations of data matrices. For derivation of the moments, exact and large sample asymptotic distributions of the sample ratios are reviewed but neither can be applicable to derivation of the moments. Therefore, I rely on simulations, where data …
On Distribution Function Estimation Using Double Ranked Set Samples With Application, Walid A. Abu-Dayyeh, Hani M. Samawi, Lara A. Bani-Hani
On Distribution Function Estimation Using Double Ranked Set Samples With Application, Walid A. Abu-Dayyeh, Hani M. Samawi, Lara A. Bani-Hani
Journal of Modern Applied Statistical Methods
As a variation of ranked set sampling (RSS); double ranked set sampling (DRSS) was introduced by Al-Saleh and Al-Kadiri (2000), and it has been used only for estimating the mean of the population. In this paper DRSS will be used for estimating the distribution function (cdf). The efficiency of the proposed estimators will be obtained when ranking is perfect. Some inference on the distribution function will be drawn based on Kolomgrov-Smirnov statistic. It will be shown that using DRSS will increase the efficiency in this case.
A Program For Generating All Permutations Of {1, 2, ..., N}, Robert Disario
A Program For Generating All Permutations Of {1, 2, ..., N}, Robert Disario
Journal of Modern Applied Statistical Methods
A Visual Basic program that generates all permutations of {1, 2, ..., n} is presented. The procedure for running the program as an Excel macro is described. An application is presented which involves selecting permutations which meet a specific constraint.
Chronic Disease Data And Analysis: Current State Of The Field, Ralph D'Agostino Sr., Lisa M. Sullivan
Chronic Disease Data And Analysis: Current State Of The Field, Ralph D'Agostino Sr., Lisa M. Sullivan
Journal of Modern Applied Statistical Methods
Chronic disease usually spans years of a person’s lifetime and includes a disease free period, a preclinical, or latent period, where there are few overt signs of disease, a clinical period where the disease manifests and is eventually diagnosed, and a follow-up period where the disease might progress steadily or remain stable. It is often of interest to investigate the relationship between risk factors measured at a point in time (usually during the disease free or preclinical period), and the development of disease at some future point (e.g., 10 years later). We outline some popular designs for the identification of …
Shifting Goals And Mounting Challenges For Statistical Methodology, Pranab K. Sen
Shifting Goals And Mounting Challenges For Statistical Methodology, Pranab K. Sen
Journal of Modern Applied Statistical Methods
Modern interdisciplinary research in statistical science encompasses a wide field: agriculture, biology, biomedical sciences along with bioinformatics, clinical sciences, education, environmental and public health disciplines, genomic science, industry, molecular genetics, socio-behavior, socio-economics, toxicology, and a variety of other disciplines. Statistical science has historically had mathematical perspectives dominating theoretical and methodological developments. Yet, the advent of modern information technology has opened the doors for highly computation intensive statistical tools (i.e., software), wherein mathematical aspects are often de-emphasized. Knowledge discovery and data mining (KDDM) is now becoming a dominating force, with bioinformatics as a notable example. In view of this apparent discordance …
Combining Two Nonparametric Tests Of Location, R. Clifford Blair
Combining Two Nonparametric Tests Of Location, R. Clifford Blair
Journal of Modern Applied Statistical Methods
A distribution-free test is proposed whose power is similar to that of the Wilcoxon Rank-Sum or Terry-Hoeffding Normal Scores tests depending on which of these two tests is more powerful in a given data analysis situation, regardless of the population. This new statistic is distribution-free, and adds no new assumptions to those associated with the constituent tests. A table of critical values for the new statistic is given and some of its Type I error and power properties are examined.
Power Analyses When Comparing Trimmed Means, Rand R. Wilcox, H. J. Keselman
Power Analyses When Comparing Trimmed Means, Rand R. Wilcox, H. J. Keselman
Journal of Modern Applied Statistical Methods
Given a random sample from each of two independent groups, this article takes up the problem of estimating power, as well as a power curve, when comparing 20% trimmed means with a percentile bootstrap method. Many methods were considered, but only one was found to be satisfactory in terms of obtaining both a point estimate of power as well as a (one-sided) confidence interval. The method is illustrated with data from a reading study where theory suggests two groups should differ but nonsignificant results were obtained.
Some Locally Most Powerful Rank Tests For Correlation, W. J. Conover
Some Locally Most Powerful Rank Tests For Correlation, W. J. Conover
Journal of Modern Applied Statistical Methods
Four examples are given to illustrate the ease and practicality of the procedure for finding locally most powerful rank tests for correlation. The first two examples deal with bivariate exponential models. The third example uses the bivariate normal distribution, and the fourth example analyzes the Morgenstem’s general correlation model.
Exact Level And Power Of Permutation, Bootstrap, And Asymptotic Tests Of Trend, Christopher D. Corcoran, Cyrus R. Mehta
Exact Level And Power Of Permutation, Bootstrap, And Asymptotic Tests Of Trend, Christopher D. Corcoran, Cyrus R. Mehta
Journal of Modern Applied Statistical Methods
We develop computational tools that can evaluate the exact size and power of three tests of trend (e.g., permutation, bootstrap and asymptotic) without resorting to large-sample theory or simulations. We then use these tools to compare the operating characteristics of the three tests. It is seen that the bootstrap test is ultra-conservative relative to the other two tests and as a result suffers from a severe deterioration in power. The power of the asymptotic test is uniformly larger than that of the other two tests, but it fails to preserve the Type I error for most of the range of …
An Adaptive Inference Strategy: The Case Of Auditory Data, Bruno D. Zumbo
An Adaptive Inference Strategy: The Case Of Auditory Data, Bruno D. Zumbo
Journal of Modern Applied Statistical Methods
By way of an example some of the basic features in the derivation and use of adaptive inferential methods are demonstrated. The focus of this paper is dyadic (coupled) data in auditory and perceptual research. We present: (a) why one should not use the conventional methods, (b) a derivation of an adaptive method, and (c) how the new adaptive method works with the example data. In the concluding remarks we draw attention to the work of Professor George Barnard who provided the adaptive inference strategy in the context of the Behrens-Fisher problem -- testing the equality of means when one …
Hotelling's T2 Vs. The Rank Transform With Real Likert Data, Michael J. Nanna
Hotelling's T2 Vs. The Rank Transform With Real Likert Data, Michael J. Nanna
Journal of Modern Applied Statistical Methods
Monte Carlo research has demonstrated that there are many applications of the rank transformation that result in an invalid procedure. Examples include the two dependent samples, the factorial analysis of variance, and the factorial analysis of covariance layouts. However, the rank transformation has been shown to be a valid and powerful test in the two independent samples layout. This study demonstrates that the rank transformation is also a robust and powerful alternative to the Hotellings T2 test when the data are on a Likert scale.
Six Modifications Of The Aligned Rank Transform Test For Interaction, Kathleen Peterson
Six Modifications Of The Aligned Rank Transform Test For Interaction, Kathleen Peterson
Journal of Modern Applied Statistical Methods
Testing for interactions in multivariate experiments is an important function. Studies indicate that much data from social studies research is not normally distributed, thus violating that assumption of the AN OVA procedure. The aligned rank transformation test (ART), aligning using the means of columns and rows, has been found, in limited situations, to be robust to Type I error rates and to have greater power than the ANOVA. This study explored a variety of alignments, including the median, Winsorized trimmed means (10%) and (20%), the Huber1.28 M-estimator, and the Harrell-Davis estimator of the median. Results are reported for Type …
Applying Spatial Randomness To Community Inclusion, Michael Wolf-Branigin
Applying Spatial Randomness To Community Inclusion, Michael Wolf-Branigin
Journal of Modern Applied Statistical Methods
A spatial analytic methodology incorporating true locations is demonstrated using Monte Carlo simulations as a complement to current psychometric and quality of life indices for measuring community inclusion. Moran's I, a measure of spatial autocorrelation, is used to determine spatial dependencies in housing patterns for multiple variables, including family/friends involvement in future planning, home size, and earned income. Simulations revealed no significant spatial autocorrelation, which is a socially desirable result for housing locations for people with disabilities. Assessing the absence of clustering provides a promising methodology for measuring community inclusion.
Parametric Analyses In Randomized Clinical Trials, Vance W. Berger, Clifford E. Lunneborg, Michael D. Ernst, Jonathan G. Levine
Parametric Analyses In Randomized Clinical Trials, Vance W. Berger, Clifford E. Lunneborg, Michael D. Ernst, Jonathan G. Levine
Journal of Modern Applied Statistical Methods
One salient feature of randomized clinical trials is that patients are randomly allocated to treatment groups, but not randomly sampled from any target population. Without random sampling parametric analyses are inexact, yet they are still often used in clinical trials. Given the availability of an exact test, it would still be conceivable to argue convincingly that for technical reasons (upon which we elaborate) a parametric test might be preferable in some situations. Having acknowledged this possibility, we point out that such an argument cannot be convincing without supporting facts concerning the specifics of the problem at hand. Moreover, we have …
Two Methods To Estimate Homogenous Markov Processes, Ricardo Ocaña-Rilola
Two Methods To Estimate Homogenous Markov Processes, Ricardo Ocaña-Rilola
Journal of Modern Applied Statistical Methods
Multi-state Markov processes have been introduced recently in Health Sciences in order to study disease history events. This sort of model have some advantages respect to traditional survival analysis, therefore they are an important line of research into stochastic processes applied to Epidemiology. However these types of models increase the complexity of analysis, even for simpler processes, and standard software is limited. In this paper, two methods for fitting homogeneous Markov models are proposed and compared.
An Error In Statistical Logic In The Application Of Genetic Paternity Testing, Ernest P. Chiodo, Joseph L. Musial, J. Sia Robinson
An Error In Statistical Logic In The Application Of Genetic Paternity Testing, Ernest P. Chiodo, Joseph L. Musial, J. Sia Robinson
Journal of Modern Applied Statistical Methods
A Bayes probability computer program was written in Fortran to examine issues related to genetic paternity testing. An application was given to demonstrate the effects improper assumptions of prior probability of culpability. The seriousness of such errors include the potential of assigning paternity to wrongly accused men, or wrongly refuting paternity.
The Trouble With Trivials (P > .05), Shlomo S. Sawilowsky, Jina S. Yoon
The Trouble With Trivials (P > .05), Shlomo S. Sawilowsky, Jina S. Yoon
Journal of Modern Applied Statistical Methods
Trivials are effect sizes associated with statistically non-significant results. Trivials are like Tribbles in the Star Trek television show. They are cute and loveable. They proliferate without limit. They probably growl at Bayesians. But they are troublesome. This brief report discusses the trouble with trivials.
Using The T Test With Uncommon Sample Sizes, Shlomo S. Sawilowsky, Barry S. Markman
Using The T Test With Uncommon Sample Sizes, Shlomo S. Sawilowsky, Barry S. Markman
Journal of Modern Applied Statistical Methods
Monte Carlo techniques were used to determine the effect of using common critical values as an approximation for uncommon sample sizes. Results indicate there can be a significant loss in statistical power. Therefore, even though many instructors now rely on computer statistics packages, the recommendation is made to provide more specificity (i.e., values between 30 and 60) in tables of critical values published in textbooks.
Quantifying Bimodality Part I: An Easily Implemented Method Using Spss, B. W. Frankland, Bruno D. Zumbo
Quantifying Bimodality Part I: An Easily Implemented Method Using Spss, B. W. Frankland, Bruno D. Zumbo
Journal of Modern Applied Statistical Methods
Scientists in a variety of fields are faced with the question of whether or not a particular sample of data are best described as unimodal or bimodal. We provide a simple and convenient method for assessing bimodality. The use of the non-linear algorithms in SPSS for modeling complex mixture distributions is demonstrated on a unimodal normal distribution (with 2 free parameters) and on bimodal mixture of two normal distributions (with 5 free parameters).
Alternatives To SW In The Bracketed Interval Of The Trimmed Mean, Jennifer Bunner, Shlomo S. Sawilowsky
Alternatives To SW In The Bracketed Interval Of The Trimmed Mean, Jennifer Bunner, Shlomo S. Sawilowsky
Journal of Modern Applied Statistical Methods
The aim of this Monte Carlo study is to examine alternatives to estimated variability in building bracketed intervals about the trimmed mean.
Generation Of Combinations Using Excel, Constantine Stamatopoulos
Generation Of Combinations Using Excel, Constantine Stamatopoulos
Journal of Modern Applied Statistical Methods
Theoretical development of combinations via enumeration methods are considered. An Excel macro is provided.
Asymptotic And Exact Tests In 2 X C Ordered Categorical Contingency Tables With Statxact 2.0 - 4.0, Margaret Posch
Asymptotic And Exact Tests In 2 X C Ordered Categorical Contingency Tables With Statxact 2.0 - 4.0, Margaret Posch
Journal of Modern Applied Statistical Methods
The purpose of this study was to compare the statistical power of a variety of exact tests in the 2 x C ordered categorical contingency table using StatXact software. The Wilcoxon Rank Sum, Expected Nonnal Scores, Savage Scores (or its Log Rank equivalent), and Permutation tests were studied. Results indicated that the procedures were nearly the same in terms of comparative statistical power.
Jmasm1: Rangen 2.0 (Fortran 90/95), Gail F. Fahoome
Jmasm1: Rangen 2.0 (Fortran 90/95), Gail F. Fahoome
Journal of Modern Applied Statistical Methods
Rangen 2.0 is Fortran 90 module of subroutines used to generate uniform and nonuniform pseudo-random deviates. It includes uni1, an uniform pseudo-random number generator, and non-uniform generators based on unil. The subroutines in Rangen 2.0 were written using Essential Lahey Fortran 90, a proper subset of Fortran 90. It includes both source code for the subroutines and a short description of each subroutine, its purpose, and the arguments including data type and usage.
An Unconditional Exact Test For Small Samples Matched Binary Pairs, Robert A. Malkin
An Unconditional Exact Test For Small Samples Matched Binary Pairs, Robert A. Malkin
Journal of Modern Applied Statistical Methods
When investigators have N pairs of binary data, a common test for an increased rate of response is McNemar's test. However, McNemar's is an approximate, conditional test. An exact, unconditional test exists, but requires restrictive assumptions. Critical values and power tables are presented for an exact, unconditional test free of these assumptions.