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Articles 271 - 300 of 412

Full-Text Articles in Statistics and Probability

Net Reclassification Indices For Evaluating Risk Prediction Instruments: A Critical Review, Kathleen F. Kerr, Zheyu Wang, Holly Janes, Robyn Mcclelland, Bruce M. Psaty, Margaret S. Pepe Aug 2013

Net Reclassification Indices For Evaluating Risk Prediction Instruments: A Critical Review, Kathleen F. Kerr, Zheyu Wang, Holly Janes, Robyn Mcclelland, Bruce M. Psaty, Margaret S. Pepe

UW Biostatistics Working Paper Series

Background Net Reclassification Indices (NRI) have recently become popular statistics for measuring the prediction increment of new biomarkers.

Methods In this review, we examine the various types of NRI statistics and their correct interpretations. We evaluate the advantages and disadvantages of the NRI approach. For pre-defined risk categories, we relate NRI to existing measures of the prediction increment. We also consider statistical methodology for constructing confidence intervals for NRI statistics and evaluate the merits of NRI-based hypothesis testing.

Conclusions Investigators using NRI statistics should report them separately for events (cases) and nonevents (controls). When there are two risk categories, the …


Examining Introductory Students’ Attitudes In A Randomization-Based Curriculum, Joshua Ryan Beemer Jun 2013

Examining Introductory Students’ Attitudes In A Randomization-Based Curriculum, Joshua Ryan Beemer

Statistics

Student attitudes regarding introductory statistics courses are not always the most positive. The purpose of this research is to utilize the Survey of Attitudes Toward Statistics to evaluate introductory statistics students’ attitudes pre- and post course. Furthermore, comparisons of attitudes within different introductory course curricula across institutions will be made. Various components within the survey, such as difficulty, value, and interest, will be assessed in order to determine where students’ attitudes are affected the most and how they are correlated with other variables such as current GPA and curriculum taught. The outcomes for these models look at demographic predictors that …


P-Values Versus Significance Levels, Phillip I. Good May 2013

P-Values Versus Significance Levels, Phillip I. Good

Journal of Modern Applied Statistical Methods

In this article Phillip Good responds to Richard Anderson's article Conceptual Distinction between the Critical p Value and the Type I Error Rate in Permutation Testing.


Conceptual Distinction Between The Critical P Value And The Type I Error Rate In Permutation Testing: Author Response To Peer Comments, Richard B. Anderson May 2013

Conceptual Distinction Between The Critical P Value And The Type I Error Rate In Permutation Testing: Author Response To Peer Comments, Richard B. Anderson

Journal of Modern Applied Statistical Methods

Richard Anderson responds to comments regarding his target article Conceptual Distinction between the Critical p Value and the Type I Error Rate in Permutation Testing.


Conceptual Distinction Between The Critical P Value And The Type I Error Rate In Permutation Testing, Richard B. Anderson May 2013

Conceptual Distinction Between The Critical P Value And The Type I Error Rate In Permutation Testing, Richard B. Anderson

Journal of Modern Applied Statistical Methods

To counter past assertions that permutation testing is not distribution-free, this article clarifies that the critical p value (alpha) in permutation testing is not a Type I error rate and that a test's validity is independent of the concept of Type I error.


A Response To Anderson's (2013) Conceptual Distinction Between The Critical P Value And Type I Error Rate In Permutation Testing, Fortunato Pesarin, Stefano Bonnini May 2013

A Response To Anderson's (2013) Conceptual Distinction Between The Critical P Value And Type I Error Rate In Permutation Testing, Fortunato Pesarin, Stefano Bonnini

Journal of Modern Applied Statistical Methods

Pesarin and Bonnini respond to Anderson's (2013) Conceptual Distinction between the Critical p value and Type I Error Rate in Permutation Testing


Customer Age As A Predictor Of Contact Volume, Tollan Renner Apr 2013

Customer Age As A Predictor Of Contact Volume, Tollan Renner

Honors Theses and Capstones

A two stage modeling approach for modeling customer age as a predictor of contact volume was conducted using a real-world data set of approximately 2,000,000 contacts from a company call center. Two models were constructed in the first stage, one a straightforward regression and the other a series of regressions. One was selected as better performing and scaled up to predict calls received from calls answered. The second stage of the modeling included a day of the week covariate and performed the best of the models created. This model uses age bins as model effects, of which the youngest age …


Extensions For The Epsilon Skew Exponential Power Distribution Family, Ahmad N. Flaih Mar 2013

Extensions For The Epsilon Skew Exponential Power Distribution Family, Ahmad N. Flaih

Theses and Dissertations

Practical applied statistics reveals that the analysis of many real data that exhibit both fat-tailless and skewness shows significant departures from normality assumptions. In these circumstances, the adoption of more flexible models that cope with near normal data may be appropriate in place of adopting the robust approach, semi-parametric or nonparametric models, and Box-Cox transformation. An alternative approach is to consider using the Epsilon Skew Exponential Power (ESEP) distribution developed by Elsalloukh [12] and [15] which embeds the normal, fat-tailedness, and skewness distributions as special cases. We develop models based on using the ESEP family, in particular, the ESEP receiver …


Views On Sexual Assault Among Ifc Fraternities, Steven Legore Mar 2013

Views On Sexual Assault Among Ifc Fraternities, Steven Legore

Statistics

The data collection and analysis for this project was performed for a consulting client Cierra, a fourth year Sociology major that works at the Safer Office on campus. She went to the consulting center on campus for help with the analysis of her project. She wanted to survey the IFC fraternities at Cal Poly on their views on sexual assault and rape. Thirteen IFC fraternities were surveyed with a total of 488 respondents. The responses to the 30 question True/False survey were used to evaluate the respondent’s empathy towards women, hostility towards women, and sexual aggression. Another research interest was …


Investigation Of A Pregnancy Lifestyle Intervention Using Mediation Analysis And A Power Analysis Simulation, Kelsey Grantham Jan 2013

Investigation Of A Pregnancy Lifestyle Intervention Using Mediation Analysis And A Power Analysis Simulation, Kelsey Grantham

Statistics

No abstract provided.


A Method For Generating Realistic Correlation Matrices, Johanna S. Hardin, Stephan Ramon Garcia, David Golan Jan 2013

A Method For Generating Realistic Correlation Matrices, Johanna S. Hardin, Stephan Ramon Garcia, David Golan

Pomona Faculty Publications and Research

Simulating sample correlation matrices is important in many areas of statistics. Approaches such as generating Gaussian data and finding their sample correlation matrix or generating random uniform $[-1,1]$ deviates as pairwise correlations both have drawbacks. We develop an algorithm for adding noise, in a highly controlled manner, to general correlation matrices. In many instances, our method yields results which are superior to those obtained by simply simulating Gaussian data. Moreover, we demonstrate how our general algorithm can be tailored to a number of different correlation models. Using our results with a few different applications, we show that simulating correlation matrices …


Raman Spectroscopy For The Identification Of Body Fluid Traces : Mixtures And Contaminations, Race And Gender Differentation, Aliaksandra Sikirzhytskaya Jan 2013

Raman Spectroscopy For The Identification Of Body Fluid Traces : Mixtures And Contaminations, Race And Gender Differentation, Aliaksandra Sikirzhytskaya

Legacy Theses & Dissertations (2009 - 2024)

Body fluid traces are an important type of forensic evidence, which play a significant role in the reconstruction of a violent crime and often help to identify a victim or suspect based on DNA analysis. Despite a great need, there is no a single method, which could identify multiple body fluids. In addition, majority of current methods are destructive for the evidence. For about eight years, our laboratory has been working on the development of a new nondestructive method for identification of body fluid traces based on Raman microspectroscopy combined with advanced statistics. High differentiation power of the method has …


Student Fact Book, Fall 2013, Thirty-Seventh Annual Edition, Wright State University, Office Of Student Information Systems, Wright State University Jan 2013

Student Fact Book, Fall 2013, Thirty-Seventh Annual Edition, Wright State University, Office Of Student Information Systems, Wright State University

Wright State University Student Fact Books

The student fact book has general demographic information on all students enrolled at Wright State University for Fall Semester, 2013.


The Complete Plus-Minus: A Case Study Of The Columbus Blue Jackets, Nathan Spagnola Jan 2013

The Complete Plus-Minus: A Case Study Of The Columbus Blue Jackets, Nathan Spagnola

Theses and Dissertations

A new hockey statistic termed the Complete Plus-Minus (CPM) was created to calculate the abilities of hockey players in the National Hockey League (NHL). This new statistic was used to analyze the Columbus Blue Jackets for the 2011-2012 season. The CPM for the Blue Jackets was created using two logistic regressions that modeled a goal being scored for and against the Blue Jackets. Whether a goal was scored for or against the team were the responses, while events on the ice were the predictors in the model. It was found that the team's poor performance was due to a weak …


Descriptive Statistical Attributes Of Special Education Datasets, Valerie Felder Jan 2013

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 …


Revising Common Core Georgia Performance Standards Statistics Lesson Plans To Better Align With Statistical Practice, Rachel Bonilla Jan 2013

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.


An Analysis Of Risk Reduction Choices In Dcis Breast Cancer Patients, Lauren Soltesz Dec 2012

An Analysis Of Risk Reduction Choices In Dcis Breast Cancer Patients, Lauren Soltesz

Statistics

The main focus of this paper was to evaluate possible demographic and clinical characteristics associated with a woman’s choice of breast conserving surgery (BCS), unilateral mastectomy (ULM), or bilateral risk reduction mastectomy (BRRM). The cohort consisted of patients presenting to the City of Hope National Medical Center with ductal carcinoma in situ breast cancer who elected to have cancer directed surgery (N=305). Analyses to examine associations of patient characteristics with type of surgery were conducted using a multinomial logistic regression. Results showed that older women were more likely to choose breast conserving surgery over bilateral risk reduction mastectomy than younger …


A Descriptive Study Of Childhood Cancer Statistics: Montgomery County, Jamie L. Hartig Oct 2012

A Descriptive Study Of Childhood Cancer Statistics: Montgomery County, Jamie L. Hartig

Master of Public Health Program Student Publications

Objective: This research describes childhood cancer and identifies variances in childhood cancer statistics in the United States, Ohio, and Montgomery County.

Methods: This is a descriptive analysis of childhood cancer statistics using the Ohio Cancer Incidence Surveillance System (OCISS) (Ohio Department of Health, 2010) and CDC Wonder database (United States Department of Health and Human Services [USDHHS], Centers for Disease Control and Prevention [CDC], & National Cancer Institute [NCI], 2008 & 2011.) Cancer incidences between white children and black children were compared for the years 1999-2009. The OCISS database was also used to compare vital status by race, cancer stage …


The Dirty “S” Word: Innovative Teaching Techniques For Counselor Educators Facilitating Learning In Statistics And Research, Rebecca L. Tadlock-Marlo, Megan Michalak Oct 2012

The Dirty “S” Word: Innovative Teaching Techniques For Counselor Educators Facilitating Learning In Statistics And Research, Rebecca L. Tadlock-Marlo, Megan Michalak

Faculty Research & Creative Activity

Innovative pedagogy will be presented and discussed to help make research a less painful class to both teach and learn. Foci include teaching methods, potential assignments, and suggestions for activities to help facilitate a more fluid learning process for counselors. Attendees will explore aspects of helping students overcome their fear of both statistics and research.


From Unbiased Numerical Estimates To Unbiased Interval Estimates, Baokun Li, Gang Xiang, Vladik Kreinovich, Panagios Moscopoulos Aug 2012

From Unbiased Numerical Estimates To Unbiased Interval Estimates, Baokun Li, Gang Xiang, Vladik Kreinovich, Panagios Moscopoulos

Departmental Technical Reports (CS)

One of the main objectives of statistics is to estimate the parameters of a probability distribution based on a sample taken from this distribution. Of course, since the sample is finite, the estimate X is, in general, different from the actual value x of the corresponding parameter. What we can require is that the corresponding estimate is unbiased, i.e., that the mean value of the difference X - x is equal to 0: E[X] = x. In some problems, unbiased estimates are not possible. We show that in some such problems, it is possible to have interval unbiased estimates, i.e., …


The Gaise College Report: The American Statistical Association Meets Sound Pedagogy In Central Virginia, Beverly Wood Aug 2012

The Gaise College Report: The American Statistical Association Meets Sound Pedagogy In Central Virginia, Beverly Wood

Publications

Research in undergraduate statistics education often centers on the introductory course required for a large percentage of college students. While acknowledging the diverse setting, audience, and purpose of introductory courses, existing research assumes that courses offered by different disciplines share the same goals and teaching practices. The purpose of this study is to examine the objectives for student outcomes and pedagogical delivery of introductory statistics courses in various academic departments to provide explicit evidence for this assumption. The American Statistical Association’s Guidelines for Assessment and Instruction in Statistics Education (GAISE) are meant to apply to all introductory courses. The College …


Mathematics And The Hunger Games, Michael A. Lewis Jul 2012

Mathematics And The Hunger Games, Michael A. Lewis

Journal of Humanistic Mathematics

The Hunger Games plot features a dystopian future in which twelve outer districts are oppressed by a centralized capital. The story focuses on the heroism of a sixteen-year-old girl named Katniss and how she tries to rise above the oppression that she experiences. It also features a special lottery and other twists that are sources of mathematical interest. This essay focuses on some of the mathematical issues raised by The Hunger Games in an effort to show that this story can be used to teach students (as well as other interested parties) some important concepts from mathematics.


Adaptive Randomization Designs, Jenna Colavincenzo Jun 2012

Adaptive Randomization Designs, Jenna Colavincenzo

Statistics

Adaptive design methodologies use prior information to develop a clinical trial design. The goal of an adaptive design is to maintain the integrity and validity of the study while giving the researcher flexibility in identifying the optimal treatment. An example of an adaptive design can be seen in a basic pharmaceutical trial. There are three phases of the overall trial to compare treatments and experimenters use the information from the previous phase to make changes to the subsequent phase before it begins.

Adaptive design methods have been in practice since the 1970s, but have become increasingly complex ever since. One …


Lifestyle Choices In Relation To Bmi And Blood Pressure, Shawna Perry Jun 2012

Lifestyle Choices In Relation To Bmi And Blood Pressure, Shawna Perry

Statistics

Cal Poly currently has one of the largest ongoing university health studies in the United States. Launched in Fall 2009, the Cal Poly FLASH study, led by the Kinesiology department and STRIDE, is a longitudinal study that tracks the classes of 2013 and 2014 through online surveys and physical assessments. The data collected covers various areas such as perceived health, lifestyle choices, and actual physical health.

My project analyzed the FLASH data to investigate the relationship between various perceived variables and actual health measures for Cal Poly freshmen. The motivation for this analysis was an interest in both diet and …


Using The R Library Rpanel For Gui-Based Simulations In Introductory Statistics Courses, Ryan M. Allison May 2012

Using The R Library Rpanel For Gui-Based Simulations In Introductory Statistics Courses, Ryan M. Allison

Statistics

As a student, I noticed that the statistical package R (http://www.r-project.org) would have several benefits of its usage in the classroom. One benefit to the package is its free and open-source nature. This would be a great benefit for instructors and students alike since it would be of no cost to use, unlike other statistical packages. Due to this, students could continue using the program after their statistical courses and into their professional careers. It would be good to expose students while they are in school to a tool that professionals use in industry. R also has powerful …


When 10 Trials Are Better Than 1000: An Evidentiary Perspective On Trial Sampling, Edward K. Cheng Mar 2012

When 10 Trials Are Better Than 1000: An Evidentiary Perspective On Trial Sampling, Edward K. Cheng

Vanderbilt Law School Faculty Publications

In many mass tort cases, separately trying all individual claims is impractical, and thus a number of trial courts and commentators have explored the use of statistical sampling as a way of efficiently processing claims. Most discussions on the topic, however, implicitly assume that sampling is a “second best” solution: individual trials are preferred for accuracy, and sampling only justified under extraordinary circumstances. This Essay explores whether this assumption is really true. While intuitively one might think that individual trials would be more accurate at estimating liability than extrapolating from a subset of cases, the Essay offers three ways in …


Changes Across 25 Years Of Statistics In Medicine, Johanna S. Hardin Jan 2012

Changes Across 25 Years Of Statistics In Medicine, Johanna S. Hardin

Pomona Faculty Publications and Research

[This piece is a series of interviews with giants in the field of medicine on their views of how statistics is changing medicine. I interviewed the editor of the New England Journal of Medicine, a preeminent doctor/researcher of lung cancer, the director of the LA County Department of Public Health, and a Harvard statistician who sits on the editorial board of the New England Journal of Medicine.]


Medicine, Statistics, And Education: The Inextricable Link, Katharine K. Brieger '11, Johanna S. Hardin Jan 2012

Medicine, Statistics, And Education: The Inextricable Link, Katharine K. Brieger '11, Johanna S. Hardin

Pomona Faculty Publications and Research

No abstract provided.


The Dirty “S” Word: Innovative Teaching Techniques For Counselor Educators Facilitating Learning In Statistics And Research, Rebecca Tadlock-Marlo, Megan Michalak Jan 2012

The Dirty “S” Word: Innovative Teaching Techniques For Counselor Educators Facilitating Learning In Statistics And Research, Rebecca Tadlock-Marlo, Megan Michalak

Faculty Research & Creative Activity

Innovative pedagogy will be presented and discussed to help make research a less painful class to both teach and learn. Foci include teaching methods, potential assignments, and suggestions for activities to help facilitate a more fluid learning process for counselors. Attendees will explore aspects of helping students overcome their fear of both statistics and research.


Student Fact Book, Fall 2012, Thirty-Sixth Annual Edition, Wright State University, Office Of Student Information Systems, Wright State University Jan 2012

Student Fact Book, Fall 2012, Thirty-Sixth Annual Edition, Wright State University, Office Of Student Information Systems, Wright State University

Wright State University Student Fact Books

The student fact book has general demographic information on all students enrolled at Wright State University for Fall Quarter, 2012.