Unbiased estimators for the variance of MMD estimators

The maximum mean discrepancy (MMD) is a kernel-based distance between probability distributions useful in many applications (Gretton et al. 2012), bearing a simple estimator with pleasing computational and statistical properties. Being able to efficiently estimate the variance of this estimator is very helpful to various problems in two-sample testing. Towards this end, Bounliphone et al. (2016) used the theory of U-statistics to derive estimators for the variance of an MMD estimator, and differences between two such estimators. Their estimator, however, drops lower-order terms, and is unnecessarily biased. We show in this note - extending and correcting work of Sutherland et al. (2017) - that we can find a truly unbiased estimator for the actual variance of both the squared MMD estimator and the difference of two correlated squared MMD estimators, at essentially no additional computational cost.Comment: Fixes and extends the appendices of arXiv:1611.04488 and arXiv:1511.0458

Evaluating a Safe Space Training for Professional School Counselors and Trainees Using a Randomized Control Group Design

School counselors need to advocate and act as an ally for all students. Safe Space, a training designed to facilitate competency for working with and serving LGBTQ youth (i.e., LGBTQ competency), has received increased attention in the field of school counseling. However, limited empirical support exists for training interventions such as Safe Space, with only one study to date examining its effectiveness for graduate psychology students (see Finkel, Storaasli, Bandele, & Schaefer, 2003). This study used a randomized pretest-posttest control group design to evaluate and examine the impact of Safe Space training on competency levels of a sample of school counselors/school counselor trainees and to explore the relationship between LGBTQ competency and awareness of sexism and heterosexism

Surgical approaches to adenocarcinoma of the gastroesophageal junction: the Siewert II conundrum.

BACKGROUND: The Siewert classification system for gastroesophageal junction adenocarcinoma has provided morphological and topographical information to help guide surgical decision-making. Evidence has shown that Siewert I and III tumors are distinct entities with differing epidemiologic and histologic characteristics and distinct patterns of disease progression, requiring different treatment. Siewert II tumors share some of the characteristics of type I and III lesions, and the surgical approach is not universally agreed upon. Appropriate surgical options include transthoracic esophagogastrectomy, transhiatal esophagectomy, and transabdominal extended total gastrectomy. PURPOSE: A review of the available evidence of the surgical management of Siewert II tumors is presented. CONCLUSIONS: Careful review of the data appear to support the fact that a satisfactory oncologic resection can be achieved via a transabdominal extended total gastrectomy with a slight advantage in terms of perioperative complications, and overall postoperative quality of life. Overall and disease-free survival compares favorably to the transthoracic approach. These results can be achieved with careful selection of patients balancing more than just the Siewert type in the decision-making but considering also preoperative T and N stages, histological type (diffuse type requiring longer margins that are not always achievable via gastrectomy), and the presence of Barrett\u27s esophagus

School Counselor Competency and Lesbian, Gay, Bisexual, Transgender, and Questioning (LGBTQ) Youth

Much research has been dedicated to the difficulties LGBTQ individuals face. Further, school counselors have been challenged to assist LGBTQ individuals in the school setting. Being aware of the specific issues and being educated about specific ways to assist these individuals enable school counselors to be more effective clinicians (DePaul, Walsh, & Dam, 2009). This article will address three components of counselor preparation and affirmative school counseling interventions: counselor self-awareness, LGBTQ sexual identity development, and LGBTQ-affirmative school climate. For each component, an activity is presented to assist professional school counselors become more LGBTQ-affirmative

Two-Stage Approach for Forensic Handwriting Analysis

Trained experts currently perform the handwriting analysis required in the criminal justice field, but this can create biases, delays, and expenses, leaving room for improvement. Prior research has sought to address this by analyzing handwriting through feature-based and score-based likelihood ratios for assessing evidence within a probabilistic framework. However, error rates are not well defined within this framework, making it difficult to evaluate the method and can lead to making a greater-than-expected number of errors when applying the approach. This research explores a method for assessing handwriting within the Two-Stage framework, which allows for quantifying error rates as recommended by a federal report by PCAST (Forensic Science in Criminal Courts: Ensuring Scientific Validity of Feature Comparison Methods). The coincidence probabilities produced here can be used in later research to asses error rates using a ROC curve