Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 108 for “"type I error"”.
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The Impact Of Nested Testing On Experiment-Wise Type I Error Rate
… the initial risk that must be considered is a Type I error, also known as a false positive. The Type I error rate is set by nominal alpha, assuming all underlying conditions of the statistic are met. Experiment-wise Type I error inflation occurs when multiple tests are conducted overall for a …
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A type I error investigation of modified Scheffe-based multiple-comparison procedures in factorial ANOVA, MANOVA, and multiple-regression situations
… who are concerned with maintaining familywise Type I error rates while increasing statistical power are encouraged to consider these improved multiple-comparison methods.
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Formulating a Dimtest-Based Effect Size Measure and a New DIMTEST Statistic and Their Applications
… DIMTEST statistic (NEWDIM) that yields improved Type I error rates relative to the original DIMTEST T statistic. Furthermore, this chapter evaluates the performances of DESM and NEWDIM in terms of Type I error and power. DESM used in tandem with DIMTEST results in better Type I error rates …
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The interactive effects of data categorization and noncircularity on the sampling distribution of generalizability coefficients in analysis of variance models : an empirical investigation
… fully-crossed balanced designs as well as on the Type I error rates for F tests in repeated measures ANOVA designs. Computer programs were developed to conduct a series of simulations under various sampling conditions. Five independent parameters were considered in the simulations: (a)three levels …
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A Novel Correction for the Multivariate Ljung-Box Test
… deviations of the original test from the nominal Type I error rates under almost all scenarios. Prior attempts to mitigate this issue have been directed at modification of the test statistics or correction of the test distribution to achieve precise results in finite samples. In previous studies, …
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Bayesian Methods for the Design and Analysis of Cluster Randomised Controlled Trials
… is quantified in the context of the impact on type I error and statistical power. It is demonstrated that the adoption of these methods has the potential to reduce sample size requirements, thereby facilitating more efficient trial design and reducing research waste. However, it is also shown …
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Performance of the Kenward-Project when the Covariance Structure is Selected Using AIC and BIC
… sizes. Our study used simulations to investigate Type I error rates in test of fixed effects using Wald statistics with the KR adjustment method, incorporating the selection of the covariance structure using AIC and BIC. Performance of the AIC and BIC criteria in selecting the true covariance …
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On comparing different tests of the same hypothesis
… the power curves of each test for a fixed Type I error. However, the power curves give only an indication of the individual performances of each test and not of the extent to which they agree when applied to the same problem. The procedures discussed in this paper deal with determining this …
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Nonparametric statistical procedures for therapeutic clinical trials with survival endpoints
… are performed to investigate the actual type I error of the proposed bootstrap procedures. It is found that the type I error of the bootstrap BC confidence interval procedure is close to the nominal level when censoring is not heavy and the boosttrap percentile confidence interval …
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Infection with MCPyV, KIV, WUV, and HPV as potential risk factors for lung cancer
… LBMA data, we generated 10,000 Monte Carlo-type simulations of log-normal antibody distributions (exposure) with 200 cases and 200 controls (outcome). We estimated type I error rates, statistical power, and bias associated with three types of analytic techniques: (a) t-tests; (b) logistic …
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The dependent samples t and wilcoxon sign rank maximum test
… The maximum test is known to restrain Type I error to nominal alpha. The maximum test as created in this study not only rids the problems encountered when choosing one test of significance over another but it also allows a researcher to obtain and interpret results without the concern …
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Machine Learning for Biostatisticians: A Hypothesis Driven Approach
… designers, particularly with respect to type I error. In this thesis, we present a study of several algorithms for the detection of interacting sets of SNPs that have been recently published, including Multi-factor Dimensionality Reduction, Support Vector Machines and Random Forests. We …
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Factor scoring methods affected by response shift in patient-reported outcomes
… factor analysis (CFA) models. CFA models are a type of LVM. Each CFA model had different sets of parameters that were invariant over time. The unconstrained (Uncon) CFA model had no invariant parameters, the constrained (Con) model had all the parameters invariant, and the partially constrained …
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A Comparison Of Ordinary Least Squares, Weighted Least Squares, And Other Procedures When Testing For The Equality Of Regression
… is violated, resulting in increased Type I error rates and reduced statistical power (Box, 1954; DeShon & Alexander, 1996; Wilcox, 1997). Overton (2001) recommended weighted least squares estimation, demonstrating that it outperformed OLS and performed comparably to various …
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Selecting an Optimal Measurement Model and Detecting Differential Item Functioning Using Bayesian Confirmatory Factor Analysis
… each invariance model. I compared the power and Type I error rates for DIF detection across conditions, and assessed the quality of estimates by calculating bias and 95% CI coverage rates for key parameters. Results indicate that although WAIC has less sampling variability than DIC, their model …
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Impact of data-dependent model selection on inference
… the data-dependent model selection approach on type I error rate through simulations. In simulations, I generate data, assuming both linear and non-linear dependence of hazard on a continuous covariate as well as no association. The generated data are then used to estimate a series of models …
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Preparing, Executing, and Designing Complex Clinical Trials Using Simulations
… for biased estimates resulting in inflated type I error or decreased power due to treatment outcome time trends or drift. When originally planned, our primary analysis did not specify an adjustment for response drift, so a post-hoc analysis with a time-adjusted model was fit using the …
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A re-examination of two major bankruptcy prediction models
… Altman and Ohlson models are developed: (1) the Type-I Error Hypothesis: the change in U.S. bankruptcy law in the 1970s increases the Type-I (classifying bankrupt firms as nonbankrupt)error rate; (2) the Type-II Error Hypothesis: the increased use ofleverage in the 1980s increases the Type-II …
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Approximate Vs. Monte Carlo Critical Values For The Winsorized T-Test
… were compared with respect to robustness to types I and II errors through Monte Carlo simulations for one and 10% Winsorized values per end.</p> <p>20% Winsorized results were generally non-robust for approximate critical values and mixed for Monte Carlo-derived critical values. With one …
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Effect of Unequal Sample Sizes on the Power of DIF Detection: An IRT-Based Monte Carlo Study with SIBTEST and Mantel-Haenszel Procedures
… unequal samples in any ratio, M-H had better Type I error rate control than SIBTEST. The results also indicated that not only the ratios, but also the sample size and the magnitude of DIF influenced the behavior of SIBTEST and M-H with regard to their error rate behavior. With small samples …
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