Statistics and Probability Commons^™

Considerations In Designing Human-Computer Interfaces For Elderly People, Drew Williams, Mohammad Arif Ul Alam, Sheikh Iqbal Ahamed, William Chu

Mathematics, Statistics and Computer Science Faculty Research and Publications

As computing devices continue to become more heavily integrated into our lives, proper design of human-computer interfaces becomes a more important topic of discussion. Efficient and useful human-computer interfaces need to take into account the abilities of the humans who will be using such interfaces, and adapt to difficulties that different users may face – such as the difficulties that elderly users must deal with. Interfaces that allow for user-specific customization, while taking into account the multiple difficulties that older users might face, can assist the elderly in properly using these newer computing devices, and in doing so possibly achieving …

Mapping And Decomposing Scale-Dependent Soil Moisture Variability Within An Inner Bluegrass Landscape, Carla Landrum

Theses and Dissertations--Plant and Soil Sciences

There is a shared desire among public and private sectors to make more reliable predictions, accurate mapping, and appropriate scaling of soil moisture and associated parameters across landscapes. A discrepancy often exists between the scale at which soil hydrologic properties are measured and the scale at which they are modeled for management purposes. Moreover, little is known about the relative importance of hydrologic modeling parameters as soil moisture fluctuates with time. More research is needed to establish which observation scales in space and time are optimal for managing soil moisture variation over large spatial extents and how these scales are …

Two Methodologies: How Well Can Universities Predict Retention, Tiffany Lynette Gregory

Electronic Theses and Dissertations

Student retention has been a long standing focus in higher education research with one of the earliest work dating back to 1937. Many researchers have proposed factors that affect a student's decision to depart from the university without successfully completing a degree. It is important to not only research different attributes and characteristics that affect student departure but it is also important to study different statistical methodologies. With the advancement in technology, new methodologies such as the Classification and Regression Tree (CART) have proven to yield significant results in a variety of research fields. As these new statistical methodologies emerge, …

Comparative Power Of The Anova, Randomization Anova, And Kruskal-Wallis Test, Jamie Gleason

Wayne State University Dissertations

The t test has been suggested to be robust to departures from normality as long as group sizes are equal and samples approach 30 or more. The F statistic has also been proposed to have the same robust qualities as the t, though researchers have suggested that because a test is robust to departures from normality, that does not necessarily make it the best test for every situation. With the increase in computing capabilities, the permutation ANOVA has been explored as an alternative to the ANOVA under non-normal conditions to rehabilitate the loss of statistical power. Since the permutation ANOVA …

Descriptive Statistical Attributes Of Special Education Datasets, Valerie Felder

Wayne State University Dissertations

ABSTRACT

Descriptive Statistical Attributes of Special Education Data Sets

by

VALERIE FELDER

December 2013

Advisor: Dr. Shlomo Sawilowsky

Major: Educational Evaluation and Research

Degree: Doctor of Philosophy

Micceri (1989) examined the distributional characteristics of 440 large-sample achievement and psychometric measures. All the distributions were found to be nonnormal at alpha = .01. Micceri indicated three factors that might contribute to a non-Gaussian error distribution in the population. The first factor is subpopulations within a target population. The second factor is ceiling effects and the third factor is treatment effects that may change the location parameter, variability, or shape of the …

Predictors Of The Number Of Under-Five Malnourished Children In Bangladesh: Application Of The Generalized Poisson Regression Model, Mohammad Mafijul Islam, Morshed Alam, Md Tariquzaman, Mohammad Alamgir Kabir, Rokhsona Pervin, Munni Begum, Md Mobarak Hossain Khan

Journal Articles: Biostatistics

BACKGROUND: Malnutrition is one of the principal causes of child mortality in developing countries including Bangladesh. According to our knowledge, most of the available studies, that addressed the issue of malnutrition among under-five children, considered the categorical (dichotomous/polychotomous) outcome variables and applied logistic regression (binary/multinomial) to find their predictors. In this study malnutrition variable (i.e. outcome) is defined as the number of under-five malnourished children in a family, which is a non-negative count variable. The purposes of the study are (i) to demonstrate the applicability of the generalized Poisson regression (GPR) model as an alternative of other statistical methods and …

How Ideas Grow: Critical Mass In The Linear Threshold Model, Hossein Alidaee

Mathematics, Statistics, and Computer Science Honors Projects

We study how ideas spread through a social network using the Linear Threshold Model. Each node i on the complete graph K_n is given a threshold Ɵ_i chosen uniformly at random from (0, 1]. This threshold indicates the fraction of the social network that must be active (or believe the idea) prior to node i becoming active. We start with an activated group of early adopters, called the seed set. Considering various scenarios, we use the probabilistic method to find lower bounds on size of a seed set which guarantees that all nodes become active with high …

Patron-Driven Acquisition And Circulation At An Academic Library: Interaction Effects And Circulation Performance Of Print Books Acquired Via Librarians’ Orders, Approval Plans, And Patrons’ Interlibrary Loan Requests, David C. Tyler, Christina D. Falci, Joyce C. Melvin, Marylou Epp, Anita M. Kreps

University of Nebraska-Lincoln Libraries: Faculty Publications

Numerous publications on patron-driven acquisition (PDA) for print books and similar materials have reported that patron-requested materials circulate more. Tying circulation to selector may be failing to address the complex of factors that contributes to items’ circulation. In the present study, the authors revisit a PDA program’s data and to determine whether PDA print books’ circulation advantage persists when the potential interactions of several additional variables are taken into account. As with prior studies, library patrons were significantly better predictors of circulation than were librarians or approval plans. However, librarians proved to be significantly better predictors than were approval plans.

Simplicial Complexes Obtained From Qualitative Probability Orders, Paul H. Edelman, Tatiana Gvozdeva, Arkadii Slinko

Vanderbilt Law School Faculty Publications

The goal of this paper is to introduce a new class of simplicial complexes that naturally generalize the threshold complexes. These will be derived from qualitative probability orders on subsets of a finite set that generalize subset orders induced by probability measures. We show that this new class strictly contains the threshold complexes and is strictly contained in the shifted complexes. We conjecture that this class of complexes is exactly the set of strongly acyclic complexes, a class that has previously appeared in the context of cooperative games. Beyond the results themselves, this new class of complexes allows us to …

Book Review: Burden Of Proof: A Review Of Math On Trial, Paul H. Edelman

Vanderbilt Law School Faculty Publications

In Math on Trial, Leila Schneps and Coralie Col­ mez write about the abuse of mathematical argu­ ments in criminal trials and how these flawed arguments "have sent innocent people to prison" (p. ix). Indeed, people "saw their lives ripped apart by simple mathematical errors." The purpose of focusing on these errors, despite mathematics' "relatively rare use in trials" (p. x), is "that many of the common mathematical fallacies that pervade the public sphere are perfectly represented by these trials. Thus they serve as ideal illustrations of these errors and of the drastic consequences that faulty reasoning has on real …

Creating A User Satisfaction Index From A Parsimonious Survey Instrument, Brian Barthel

All Graduate Theses, Dissertations, and Other Capstone Projects

In this paper we present a comprehensive method for creating a user satisfaction index using a survey instrument. First we construct a parsimonious survey instrument, using the PageRank Centrality, to measure attributes of user satisfaction. Then confirmatory factor analysis is applied to extract ``weights'' on the questions that are used in a linear model of computing the user satisfaction index. Throughout the paper an analysis of an existing data set is implemented to illustrate the proposed method. In addition the validity of the confirmatory factor model is tested using bootstrap sampling.

Participation In Perinatal Interventional Research: Which Characteristics Matter?, Hai-Yen T. Nguyen Md, Joanne Quiñones Md, Msce, Daniel G. Kiefer Md, Anita Kurt Phd, Rn, Felisa Saldutti, John C. Smulian Md, Mph

Department of Obstetrics & Gynecology

No abstract provided.

Revising Common Core Georgia Performance Standards Statistics Lesson Plans To Better Align With Statistical Practice, Rachel Bonilla

College of Graduate Studies: Theses & Dissertations

In this thesis, lesson plans provided by the Georgia Department of Education are revised to give students better exposure and practice working with real-life data. Three learning tasks and a performance task are presented covering a unit lesson on statistical regression. The development of Georgia statistics curriculum standards are reviewed and presented.

A Systematic Approach To Manage Missing Data In Pavement Management Systems, Mazin M. Al-Zou'bi

Open Access Theses & Dissertations

Pavements are an important part of the highway transportation infrastructure, accounting for the largest share of the overall investment. A tremendous amount of time and money is spent each year on the construction of new pavements, as well as on the maintenance and rehabilitation of existing pavements.

Transportation agencies use pavement management systems (PMS) for their maintenance and rehabilitation planning, programming, and budgeting. PMS are used to make decisions regarding when maintenance and rehabilitation should be applied. The systems also select what type of treatment should be applied for each pavement section in the network with clear estimations of the …

Curds And Whey: Little Miss Muffit's Contribution To Multivariate Linear Regression, John Cameron Kidd

Undergraduate Honors Capstone Projects

A common multivariate statistical problem is the prediction of two or more response variables using two or more predictor variables. The simplest model for this situation is the multivariate linear regression model. The standard least squares estimation for this model involves regressing each response variable separately on all the predictor variables. Breiman and Friedman [1] show how to take advantage of correlations among the response variables to increase the predictive accuracy for each of the response variable with an algorithm they call Curds and Whey. In this report, I describe an implementation of the Curds and Whey algorithm in …

Multiscale Analysis Of Factors That Affect The Distribution Of Sharks Throughout The Northern Gulf Of Mexico, J. Marcus Drymon, Laure Carassou, Sean P. Powers, Mark Grace, John Dindo, Brian Dzwonkowski

University Faculty and Staff Publications

Identification of the spatial scale at which marine communities are organized is critical to proper management, yet this is particularly difficult to determine for highly migratory species like sharks. We used shark catch data collected during 2006–09 from fishery- independent bottom-longline surveys, as well as biotic and abiotic explanatory data to identify the factors that affect the distribution of coastal sharks at 2 spatial scales in the northern Gulf of Mexico. Centered principal component analyses (PCAs) were used to visualize the patterns that characterize shark distributions at small (Alabama and Mississippi coast) and large (northern Gulf of Mexico) spatial scales. …

Multiplicity Adjustments For Respecification Searches In Structural Equation Models, John Appiah Kubi

Open Access Theses & Dissertations

Structural Equation Modeling (SEM), as a statistical modeling technique, is one of the most comprehensive and flexible approaches to data analysis currently available. Its use has been increasing steadily over the past few decades. Generally, it refers to a family of

techniques that employs the analysis of covariance to establish relationships among a set of variables. It allows researchers (or users) to assess the adequacy of their hypothesized models with their sample data. Often times, in assessing their models, researchers are not

only interested in the overall fit of their model but they are also interested in knowing which proposed …

Comparison Of Bayesian Nonparametric Density Estimation Methods, Adel Bedoui

Open Access Theses & Dissertations

Density estimation has a long history in statistics. There are two main approaches to density, estimation parametric and nonparametric. The first approach requires specification of a family of densities f and estimation of the unknown parameter $\theta$ using a suitable estimation method, for example, maximum likelihood estimation. This approach may be prone to bias that arises from either estimation of the parameter or from incorrect specification of the probability distribution. The second approach, does not assume a specific parametric family.

In this thesis, we implement three density estimation methods that use Bayesian nonparametric approaches utilizing Markov Chain Monte Carlo methods. …

Principal Differential Analysis: Incorporating Covariates Using Kernel Smoothers, Christopher Alfred Dodoo

Open Access Theses & Dissertations

Principal Differential Analysis is a statistical technique which suggests that a given set of functional data curves can be annihilated completely when an estimated linear differential

operator (LDO) is applied (Coddington & Levinson). The novelty of residuals as forcing functions is introduced in PDA.

This thesis builds on PDA with covariates by Jin et al, 2012 by dropping the assumption that the coefficients of the linear differential operator are a product of a function in t and v; the equivalent kernel is used to estimate the coefficient functions at target values. Incorporating covariates with kernel smoothers leads to two …

Analysis Of Vehicle Interactions On Interstate Highways: Discrete Choice And Linear System Approaches, Alicia Romo

Open Access Theses & Dissertations

The research in this dissertation developed statistical and linear system models to predict driving behavior according to driver attributes, vehicle characteristics, car-following dynamics and/or driving conditions. The scope of this research was limited to the interaction of two vehicles traveling in the same direction on interstate highways.

The statistical models proposed in this research investigated the contributions of the different vehicle types on the manner and likelihood of collision. Discrete choice models were used to estimate the probability of the types of collision (rear-end, angle and sideswipe) as functions of driver attributes, striking and struck vehicle types, pre-crash driving actions …

A New Method For The Comparison Of Survival Distributions, Jaymie Shanahan

Theses and Dissertations

The assessment of overall homogeneity of time-to-event curves is a key element in survival analysis in biomedical research. The currently commonly used testing methods, e.g. log-rank test, Wilcoxon test, and Kolmogorov-Smirnov test, may have a significant loss of statistical testing power under certain circumstances. In this thesis we replicate a testing method (Lin & Xu, 2009) that is robust for the comparison of the overall homogeneity of survival curves based on the absolute difference of the area under the survival curves using normal approximation by Greenwood's formula, and propose a new weight component to their test statistic. The weight component …

Protein Identification Using Bayesian Stochastic Search, Christina Nicole Lewis

Theses and Dissertations

Current methods for protein identification in tandem mass spectrometry (MS/MS) involve database searches or de novo peptide sequencing, with database searches being the standard method. With database searches, issues arise when the species is not in the database. Shortcomings of de novo peptide sequencing and database searches include chemical noise, overly complex fragments, and incomplete b and y ion sequences. Here we present a Bayesian approach to identifying peptides. Our model uses prior information about the average relative abundances of bond cleavages and the prior probability of any particular amino acid sequence. The proposed likelihood function is composed of two …

Initiation And Continuation Of Randomized Trials After The Publication Of A Trial Stopped Early For Benefit Asking The Same Study Question: Stopit-3 Study Design, Gabriela J. Prutsky, Juan Domecq, Patricia J. Erwin, Matthias Briel, Victor M. Montori, Elie A. Akl, Joerg J. Meerpohl, Dirk Bassler, Stefan Schandelmaier, Stephen D. Walter, Qi Zhou, Pablo Coello, Lorenzo Moja, Martin Walter, Kristian Thorlund, Paul Glasziou, Regina Kunz, Ignacio Ferreira-Gonzalez, Jason Busse, Xin Sun, Annette Kristiansen, Benjamin Kasenda, Osama Qasim-Agha, Gennaro Pagano, Hector Pardo-Hernandez, Gerard Urrutia, Mohammad Murad, Gordon Guyatt

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Randomized control trials (RCTs) stopped early for benefit (truncated RCTs) are increasingly common and, on average, overestimate the relative magnitude of benefit by approximately 30%. Investigators stop trials early when they consider it is no longer ethical to enroll patients in a control group. The goal of this systematic review is to determine how investigators of ongoing or planned RCTs respond to the publication of a truncated RCT addressing a similar question.

Methods/design

We will conduct systematic reviews to update the searches of 210 truncated RCTs to identify similar trials ongoing at the time of publication, or started …

Advanced Methodology Developments In Mixture Cure Models, Chao Cai

Theses and Dissertations

Modern medical treatments have substantially improved cure rates for many chronic diseases and have generated increasing interest in appropriate statistical models to handle survival data with non-negligible cure fractions. The mixture cure models are designed to model such data set, which assume that studied population is a mixture of being cured and uncured. In this dissertation, I will develop two programs named smcure and NPHMC in R. The first program aims to facilitate estimating two popular mixture cure models: the proportional hazards (PH) mixture cure model and accelerated failure time (AFT) mixture cure model. The second program focuses on designing …

Tracking Atlantic Hurricanes Using Statistical Methods, Elizabeth Caitlin Miller

USF Tampa Graduate Theses and Dissertations

Creating an accurate hurricane location forecasting model is of the utmost importance because of the safety measures that need to occur in the days and hours leading up to a storm's landfall. Hurricanes can be incredibly deadly and costly, but if people are given adequate warning, many lives can be spared. This thesis seeks to develop an accurate model for predicting storm location based on previous location, previous wind speed, and previous pressure. The models are developed using hurricane data from 1980-2009.

Optimization In Non-Parametric Survival Analysis And Climate Change Modeling, Iuliana Teodorescu

USF Tampa Graduate Theses and Dissertations

Many of the open problems of current interest in probability and statistics involve complicated data

sets that do not satisfy the strong assumptions of being independent and identically distributed. Often,

the samples are known only empirically, and making assumptions about underlying parametric

distributions is not warranted by the insufficient information available. Under such circumstances,

the usual Fisher or parametric Bayes approaches cannot be used to model the data or make predictions.

However, this situation is quite often encountered in some of the main challenges facing statistical,

data-driven studies of climate change, clinical studies, or financial markets, to name a few. …

Age Dependent Analysis And Modeling Of Prostate Cancer Data, Nana Osei Mensa Bonsu

USF Tampa Graduate Theses and Dissertations

Growth rate of prostate cancer tumor is an important aspect of understanding the natural history of prostate cancer. Using real prostate cancer data from the SEER database with tumor size as a response variable, we have clustered the cancerous tumor sizes into age groups to enhance its analytical behavior. The rate of change of the response variable as a function of age is given for each cluster. Residual analysis attests to the quality of the analytical model and the subject estimates. In addition, we have identified the probability distribution that characterize the behavior of the response variable and proceeded with …

The Positive Illusory Bias And Adhd Symptoms: A New Measurement Approach, Sarah A. Fefer

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to investigate perceptions of academic and social competence among adolescents with a continuum of inattentive and hyperactive/impulsive symptoms. Past literature suggests that children with Attention-Deficit/Hyperactivity Disorder (ADHD) display self-perceptions that are overly positive compared to external indicators of competence, a phenomenon that is referred to as the positive illusory bias (PIB; Owens, Goldfine, Evangelista, Hoza, & Kaiser, 2007). The PIB is well supported among children with ADHD, and recent research suggests that the PIB persists into adolescence. To date, research on the PIB has relied on difference scores (i.e., an indicator of competence is …

Effectiveness Of Propensity Score Methods In A Multilevel Framework: A Monte Carlo Study, Aarti P. Bellara

USF Tampa Graduate Theses and Dissertations

Propensity score analysis has been used to minimize the selection bias in observational studies to identify causal relationships. A propensity score is an estimate of an individual's probability of being placed in a treatment group given a set of covariates. Propensity score analysis aims to use the estimate to create balanced groups, akin to a randomized experiment. This study used Monte Carlo methods to examine the appropriateness of using propensity score methods to achieve balance between groups on observed covariates and reproduce treatment effect estimates in multilevel studies. Specifically, this study examined the extent to which four different propensity score …

A Latent Mixture Approach To Modeling Zero-Inflated Bivariate Ordinal Data, Rajendra Kadel

USF Tampa Graduate Theses and Dissertations

Multivariate ordinal response data, such as severity of pain, degree of disability, and satisfaction with a healthcare provider, are prevalent in many areas of research including public health, biomedical, and social science research. Ignoring the multivariate features of the response variables, that is, by not taking the correlation between the errors across models into account, may lead to substantially biased estimates and inference. In addition, such multivariate ordinal outcomes frequently exhibit a high percentage of zeros (zero inflation) at the lower end of the ordinal scales, as compared to what is expected under a multivariate ordinal distribution. Thus, zero inflation …