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Bridging the Gap: A Generalized Stochastic Process for Count Data
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| Pengarang | : | Li Zhu |
| Nama Majalah/Jurnal | : | The American Statistician |
| Volume / Edisi | : | 71 (No. 1) |
| Halaman | : | 71-80 |
| Abstrak | : | The Bernoulli and Poisson processes are two popular discrete count processes; however, both rely on strict assumptions. We instead propose a generalized homogenous count process (which we name the Conway–Maxwell–Poisson or COM-Poisson process) that not only includes the Bernoulli and Poisson processes as special cases, but also serves as a flexible mechanism to describe count processes that approximate data with over- or under-dispersion. We introduce the process and an associated generalized waiting time distribution with several real-data applications to illustrate its flexibility for a variety of data structures. We consider model estimation under different scenarios of data availability, and assess performance through simulated and real datasets. This new generalized process will enable analysts to better model count processes where data dispersion exists in a more accommodating and flexible manner. |
An Intuitive Geometric Approach to the Gauss Markov Theorem
| Pengarang | : | Leandro da Silva Pereira |
| Nama Majalah/Jurnal | : | The American Statistician |
| Volume / Edisi | : | 71 (No. 1) |
| Halaman | : | 67-70 |
| Abstrak | : | Algebraic proofs of Gauss–Markov theorem are very disappointing from an intuitive point of view. An alternative is to use geometry that emphasizes the essential statistical ideas behind the result. This article presents a truly geometrical intuitive approach to the theorem, based only in simple geometrical concepts, like linear subspaces and orthogonal projections. |
The Quality of Pitches in Major League Baseball
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | The American Statistician |
| Volume / Edisi | : | 71 (No. 2) |
| Halaman | : | 148-154 |
| Abstrak | : | This article considers the quality of pitches in Major League Baseball (MLB). Based on approximately 2.2 million pitches taken from the 2013, 2014, and 2015 MLB seasons, the quality of a particular pitch is evaluated as the expected number of bases conceded. Quality is expressed as a function of various covariates including pitch count, pitch location, pitch type, and pitch speed. The estimation of the pitch quality is obtained through the use of random forest methodology to accommodate the inherent complexity of the relationship between pitch quality and the associated covariates. With the fitted model, various applications are considered which provide new insights on pitching and batting. |
Experience Simpson's Paradox in the Classroom
| Pengarang | : | Jiangtao Gou |
| Nama Majalah/Jurnal | : | The American Statistician |
| Volume / Edisi | : | 71 (No. 1) |
| Halaman | : | 61-66 |
| Abstrak | : | Simpson's paradox is a challenging topic to teach in an introductory statistics course. To motivate students to understand this paradox both intuitively and statistically, this article introduces several new ways to teach Simpson's paradox. We design a paper toss activity between instructors and students in class to engage students in the learning process. We show that Simpson's paradox widely exists in basketball statistics, and thus instructors may consider looking for Simpson's paradox in their own school basketball teams as examples to motivate students’ interest. A new probabilistic explanation of Simpson's paradox is provided, which helps foster students’ statistical understanding. Supplementary materials for this article are available online. |
Explaining Normal Quantile-Quantile Plots Through Animation: The Water-Filling Analogy
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | The American Statistician |
| Volume / Edisi | : | 71 (No. 2) |
| Halaman | : | 145-147 |
| Abstrak | : | A normal quantile-quantile (QQ) plot is an important diagnostic for checking the assumption of normality. Though useful, these plots confuse students in my introductory statistics classes. A water-filling analogy, however, intuitively conveys the underlying concept. This analogy characterizes a QQ plot as a parametric plot of the water levels in two gradually filling vases. Each vase takes its shape from a probability distribution or sample. If the vases share a common shape, then the water levels match throughout the filling, and the QQ plot traces a diagonal line. An R package qqvases provides an interactive animation of this process and is suitable for classroom use. |
Mentoring to Achieve Diversity in Graduate Programs
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | The American Statistician |
| Volume / Edisi | : | 71 (No. 1) |
| Halaman | : | 55-60 |
| Abstrak | : | The discipline of statistics has a celebrated, diverse, and colorful past. With a definite international flavor, we continue to make great strides in keeping our discipline relevant and accessible for addressing significant societal concerns. Unfortunately, we lag behind many other disciplines when it comes to fully tapping into the potential of all demographic groups within the United States. Mentoring provides one of many opportunities to change this narrative. This article looks at hard numbers related to diversity, points to some existing successful mentoring programs, and is a reflection of lessons learned through personal experiences. |
Mentoring Faculty Women in Statistics: Exploring Challenges and Opportunities for Leadership Development
| Pengarang | : | Amanda L. Golbeck |
| Nama Majalah/Jurnal | : | The American Statistician |
| Volume / Edisi | : | 71 (No. 1) |
| Halaman | : | 47-54 |
| Abstrak | : | The problems for faculty women in statistics (FWIS) in the United States are complex and call for programs that aim to develop inclusive leadership competencies among both FWIS and faculty men in statistics (FMIS) regardless of whether they currently hold, or aspire to, administrative positions. Data indicate that, among faculty in doctorate-granting departments of statistics and biostatistics, there is a disparity between genders in numbers of role models or exemplars. Yet we note that there have been some innovative national initiatives over the years in mentoring, networking, or leadership that have been instrumental in advancing FWIS. Given current understandings of the role of implicit bias in sustaining a differential status for FWIS, this discussion emphasizes a new approach as a way to further advance FWIS: one that involves the development of inclusive leadership among both men and women toward promoting inclusive faculty cultures in statistics. |
Developing a Career in the Practice of Statistics: The Mentor's Perspective
| Pengarang | : | Kim Love |
| Nama Majalah/Jurnal | : | The American Statistician |
| Volume / Edisi | : | 71 (No. 1) |
| Halaman | : | 38-46 |
| Abstrak | : | The W.J. Dixon Award for Excellence in Statistical Consulting is given by the American Statistical Association to “a distinguished individual who has demonstrated excellence in statistical consulting or developed and contributed new methods, software, or ways of thinking that improve statistical practice in general.” In this article, five of the seven past recipients of this career-capping award share their experiences and perspectives through 10 stepping stones that move a practicing statistician from consultant to collaborator to leader. We highlight the need for mentorship throughout the discussion, and provide direction for statisticians who would like to incorporate this advice into their careers. |
Building Bridges: The Role of an Undergraduate Mentor
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | The American Statistician |
| Volume / Edisi | : | 71 (No. 1) |
| Halaman | : | 30-33 |
| Abstrak | : | I share some advice and lessons that I have learned from working with many wonderful students and colleagues, in my role as Undergraduate Chair of Statistics at Purdue University since 2008. I also reflect on developing, implementing, and sustaining a new living, learning community environment for statistics students. |
Re-Defining the Who, When, and Where of Mentoring for Professional Statisticians
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | The American Statistician |
| Volume / Edisi | : | 71 (No. 1) |
| Halaman | : | 34-37 |
| Abstrak | : | Organizations tailor their mentoring strategies to accommodate internal resources and preferences, producing different approaches in academic, government, and corporate environments. Across these settings, three common barriers impede effective mentoring of statisticians: overspecialization, time constraints, and geographic dispersion. The authors share mentoring strategies that have emerged at their organization, Mathematica Policy Research, to overcome these obstacles. Practices include creating a methodology working group to unite researchers with diverse backgrounds, integrating mentoring into existing workflows, and harnessing modern technological infrastructure to facilitate virtual mentoring. Although these strategies emerged within a specific professional context, they suggest opportunities for statisticians to expand the channels through which mentorship can occur. |