Adaptive Clinical Trial Designs With Pre-Specified Rules For Modifying The Sample Size: Understanding Efficient Types Of Adaptation,
2011
University of Washington
Adaptive Clinical Trial Designs With Pre-Specified Rules For Modifying The Sample Size: Understanding Efficient Types Of Adaptation, Gregory P. Levin, Sarah C. Emerson, Scott S. Emerson
UW Biostatistics Working Paper Series
Methods allowing unplanned adaptations to the sample size based on the interim estimate of treatment effect do not base inference on the minimal sufficient statistic and suffer losses in efficiency when compared to group sequential designs [1, 2, 3]. However, when adaptive sampling plans are completely pre-specified at the design stage of the trial, investigators can proceed with frequentist inference based on the minimal sufficient statistic at the analysis stage. In the context of two general settings where different optimality criteria govern the choice of clinical trial design, we quantify the relative costs and benefits of a variety of fixed …
Solving The Differential Equation For The Probit Function Using A Variant Of The Carleman Embedding Technique.,
2011
East Tennessee State University
Solving The Differential Equation For The Probit Function Using A Variant Of The Carleman Embedding Technique., Kelechukwu Iroajanma Alu
Electronic Theses and Dissertations
The probit function is the inverse of the cumulative distribution function associated with the standard normal distribution. It is of great utility in statistical modelling. The Carleman embedding technique has been shown to be effective in solving first order and, less efficiently, second order nonlinear differential equations. In this thesis, we show that solutions to the second order nonlinear differential equation for the probit function can be approximated efficiently using a variant of the Carleman embedding technique.
Power Analysis For Alternative Tests For The Equality Of Means.,
2011
East Tennessee State University
Power Analysis For Alternative Tests For The Equality Of Means., Haiyin Li
Electronic Theses and Dissertations
The two sample t-test is the test usually taught in introductory statistics courses to test for the equality of means of two populations. However, the t-test is not the only test available to compare the means of two populations. The randomization test is being incorporated into some introductory courses. There is also the bootstrap test. It is also not uncommon to decide the equality of the means based on confidence intervals for the means of these two populations. Are all those methods equally powerful? Can the idea of non-overlapping t confidence intervals be extended to bootstrap confidence intervals? The powers …
Putting Artists On The Map: A Five Part Study Of Greater Cleveland Artists' Location Decisions - Part 5: Properties Analysis - Artist Housing Characteristics,
2011
Cleveland State University
Putting Artists On The Map: A Five Part Study Of Greater Cleveland Artists' Location Decisions - Part 5: Properties Analysis - Artist Housing Characteristics, Mark Salling, Gregory Soltis, Charles Post, Sharon Bliss, Ellen Cyran
All Maxine Goodman Levin School of Urban Affairs Publications
A series of reports detailing the residential and work space location preferences of Cuyahoga county's artists.
A Range And Existence Theorem For Pseudomonotone Perturbations Of Maximal Monotone Operators,
2011
Missouri University of Science and Technology
A Range And Existence Theorem For Pseudomonotone Perturbations Of Maximal Monotone Operators, Vy Khoi Le
Mathematics and Statistics Faculty Research & Creative Works
In this paper, we prove a range and existence theorem for multivalued pseudomonotone perturbations of maximal monotone operators. We assume a general coercivity condition on the sum of a maximal monotone and a pseudomonotone operator instead of a condition on the pseudomonotone operator only. An illustrative example of a variational inequality in a Sobolev space with variable exponent is given.
Model Diagnostics For Proportional And Partial Proportional Odds Models,
2011
The Ohio State University
Model Diagnostics For Proportional And Partial Proportional Odds Models, Ann A. O'Connell, Xing Liu
Journal of Modern Applied Statistical Methods
Although widely used to assist in evaluating the prediction quality of linear and logistic regression models, residual diagnostic techniques are not well developed for regression analyses where the outcome is treated as ordinal. The purpose of this article is to review methods of model diagnosis that may be useful in investigating model assumptions and in identifying unusual cases for PO and PPO models, and provide a corresponding application of these diagnostic methods to the prediction of proficiency in early literacy for children drawn from the kindergarten cohort of the Early Childhood Longitudinal Study (ECLS-K; NCES, 2000).
Sample Size Considerations For Multiple Comparison Procedures In Anova,
2011
Ohio University
Sample Size Considerations For Multiple Comparison Procedures In Anova, Gordon P. Brooks, George A. Johanson
Journal of Modern Applied Statistical Methods
Adequate sample sizes for omnibus ANOVA tests do not necessarily provide sufficient statistical power for post hoc multiple comparisons typically performed following a significant omnibus F test. Results reported support a comparison-of-most-interest approach for sample size determination in ANOVA based on effect sizes for multiple comparisons.
Type I Error Inflation Of The Separate-Variances Welch T Test With Very Small Sample Sizes When Assumptions Are Met,
2011
Ohio University
Type I Error Inflation Of The Separate-Variances Welch T Test With Very Small Sample Sizes When Assumptions Are Met, Albert K. Adusah, Gordon P. Brooks
Journal of Modern Applied Statistical Methods
This Monte Carlo study shows that the separate-variances Welch t test has inflated Type I error rates at very small sample sizes, especially when sample sizes are very small in one group and larger in the second group – even when all assumptions for the statistical test are met.
One Is Not Enough: The Need For Multiple Respondents In Survey Research Of Organizations,
2011
Mercer University
One Is Not Enough: The Need For Multiple Respondents In Survey Research Of Organizations, Joseph L. Balloun, Hilton Barrett, Art Weinstein
Journal of Modern Applied Statistical Methods
The need for multiple respondents per organization in organizational survey research is supported. Leadership teams’ ratings of their implementations of market orientation are examined, along with learning orientation, entrepreneurial management, and organizational flexibility. Sixty diverse organizations, including not-for-profit organizations in education and healthcare as well as manufacturing and service businesses, were included. The major finding was the large rating variance within the leadership teams of each organization. The results are enlightening and have definite implications for improved design of survey research on organizations.
Is Next Twelve Months Period Tumor Recurrence Free Under Restricted Rate Due To Medication? A Probabilistic Warning,
2011
Texas State University
Is Next Twelve Months Period Tumor Recurrence Free Under Restricted Rate Due To Medication? A Probabilistic Warning, Ramalingam Shanmugam
Journal of Modern Applied Statistical Methods
A methodology is formulated to analyze tumor recurrence data when its incidence rate is restricted due to medication. Analytic results are derived to make a probabilistic early warning of tumor recurrence free period of length τ; that is, the chance for a safe period of lengthτ is estimated. The captured data are length biased. Expressions are developed to extract and relate to counterparts of the non-length biased data. Three data sets are considered as illustrations: (1) patients who are given a placebo, (2) patients who are given the medicine pyridoxine and (3) patients who are given the medicine thiotepa.
The Likelihood Of Choosing The Borda-Winner With Partial Preference Rankings Of The Electorate,
2011
University of California, Santa Barbara, CA
The Likelihood Of Choosing The Borda-Winner With Partial Preference Rankings Of The Electorate, Ömer Eğecioğlu, Ayça Ebru Giritligil
Journal of Modern Applied Statistical Methods
Given that n voters report only the first r (1 ≤ r < m) ranks of their linear preference rankings over m alternatives, the likelihood of implementing Borda outcome is investigated. The information contained in the first r ranks is aggregated through a Borda-like method, namely the r-Borda rule. Monte-Carlo simulations are run to detect changes in the likelihood of r-Borda winner(s) to coincide with the original Borda winner(s) as a function of m, n and r. The voters’ preferences are generated through the Impartial Anonymous and Neutral Culture Model, where both the names of the …
An Exact Test For The Equality Of Intraclass Correlation Coefficients Under Unequal Family Sizes,
2011
Columbus State University
An Exact Test For The Equality Of Intraclass Correlation Coefficients Under Unequal Family Sizes, Madhusudan Bhandary, Koji Fujiwara
Journal of Modern Applied Statistical Methods
An exact test for the equality of two intraclass correlation coefficients under unequal family sizes based on two independent multi-normal samples is proposed. This exact test consistently and reliably produced results superior to those of the Likelihood Ratio Test (LRT) and the large sample Z-test proposed by Young and Bhandary (1998). The test generally performed better in terms of power (for higher intraclass correlation values) for various combinations of intraclass correlation coefficient values and the exact test remained closer to the significance level under the null hypothesis compared to the other two tests. For small sample situations, sizes of the …
Extension Of Grizzle’S Classic Crossover Design,
2011
Christiana Care Hospital System, Newark, Delaware
Extension Of Grizzle’S Classic Crossover Design, James F. Reed Iii
Journal of Modern Applied Statistical Methods
The crossover design compares treatments A and B over two periods using sequences AB and BA (the AB|BA design) and is the classic design most often illustrated and critiqued in textbooks. Other crossover designs have been used but their use is relatively rare and not always well understood. This article introduces alternatives to a randomized two-treatment, two-period crossover study design. One strategy, which is to extend the classic AB|BA by adding a third period to repeat one of the two treatments, has several attractive advantages; an added treatment period may not imply a large additional cost but will allow carryover …
Double Acceptance Sampling Plans Based On Truncated Life Tests For Marshall-Olkin Extended Lomax Distribution,
2011
Dill University
Double Acceptance Sampling Plans Based On Truncated Life Tests For Marshall-Olkin Extended Lomax Distribution, G. Srinivasa Rao
Journal of Modern Applied Statistical Methods
Double Acceptance Sampling Plans (DASP) is developed for a truncated life test when the lifetime of an item follows the Marshall-Olkin extended Lomax distribution. Probability of Acceptance (PA) is calculated for different consumer’s confidence levels fixing the producer’s risk at 0.05. Probability of acceptance and producer’s risk are illustrated with examples.
Estimation Of Population Mean In Successive Sampling By Sub-Sampling Non-Respondents,
2011
Vikram University, Ujjain, India
Estimation Of Population Mean In Successive Sampling By Sub-Sampling Non-Respondents, Housila P. Singh, Sunil Kumar, Sandeep Bhougal
Journal of Modern Applied Statistical Methods
The estimation of the population mean in mail surveys is investigated in the context of sampling on two occasions where the population mean of the auxiliary variable is available in the presence of non-response only for the current occasion in two occasion successive sampling. The behavior of the proposed estimator is compared with the estimator for the same situation but in the absence of non-response. An empirical illustration demonstrates the performance of the proposed estimator.
Fisher’S Exact Test For Misclassified Data,
2011
Western Illinois University
Fisher’S Exact Test For Misclassified Data, Tze-San Lee
Journal of Modern Applied Statistical Methods
Ecole Supérieure de Commerce de Tunis. Fisher’s exact test is adapted to handle the misclassified data arising from comparing two binomial populations. The bias-adjusted odds ratio is proposed to account for misclassification errors. Its expected power depends in a nonlinear way on the true sensitivity and specificity of the classification method. The data taken from the no conviction rate of criminality for two types of twin populations was used to illustrate how to calculate true sensitivity and specificity and the expected power of the adjusted odds ratio.
Improved Estimation Of The Population Mean Using Known Parameters Of An Auxiliary Variable,
2011
Vikram University, Ujjain, M.P., India
Improved Estimation Of The Population Mean Using Known Parameters Of An Auxiliary Variable, Rajesh Tailor, Balkishan Sharma
Journal of Modern Applied Statistical Methods
An improved ratio-cum-product type estimator of the finite population mean is proposed using known information on the coefficient of variation of an auxiliary variate and correlation coefficient between a study variate and an auxiliary variate. Realistic conditions are obtained under which the proposed estimator is more efficient than the simple mean estimator, usual ratio and product estimators and estimators proposed by Singh and Diwivedi (1981), Pandey and Dubey (1988), Upadhaya and Singh (1999), and Singh, et al., (2004). An empirical study supports theoretical findings.
Inference In Simple Regression For The Intercept Utilizing Prior Information On The Slope,
2011
Qatar University
Inference In Simple Regression For The Intercept Utilizing Prior Information On The Slope, Ayman Baklizi, Adil E. Yousif
Journal of Modern Applied Statistical Methods
Shrinkage type estimators are developed for the intercept parameter of a simple linear regression model and the case when it is suspected a priori that the slope parameter is equal to some specific value is considered. Three different estimators of the intercept parameters are examined. The relative performances of the estimators are investigated based on a simulation study of the biases and mean squared errors. The associated bootstrap confidence intervals are also studied and their performance is evaluated.
Factors Influencing The Mixture Index Of Model Fit In Contingency Tables Showing Independence,
2011
IBM Global Business Services
Factors Influencing The Mixture Index Of Model Fit In Contingency Tables Showing Independence, Xuemei Pan, C. Mitchell Dayton
Journal of Modern Applied Statistical Methods
Several competing computational techniques for dealing with sampling zeros were evaluated when estimating the two-point mixture model index, π* , in contingency tables under an independence assumption. Also, the performance of the estimate and associated standard errors were studied under various combinations of conditions.
Bayesian Regression Analysis With Examples In S-Plus And R,
2011
University of Kashmir, Srinagar, India
Bayesian Regression Analysis With Examples In S-Plus And R, Sheikh P. Ahmad, A. A. Khan, A. Ahmed
Journal of Modern Applied Statistical Methods
An extended version of normal theory Bayesian regression models, including extreme-value, logistic and normal regression models is examined. Methods proposed are illustrated numerically; the regression coefficient of pH on electrical conductivity (EC) of soil data is analyzed using both S-PLUS and R software.
