Wilcoxon's signed‐rank statistic: what null hypothesis and why it matters

In statistical literature, the term ‘signed‐rank test’ (or ‘Wilcoxon signed‐rank test’) has been used to refer to two distinct tests: a test for symmetry of distribution and a test for the median of a symmetric distribution, sharing a common test statistic. To avoid potential ambiguity, we propose to refer to those two tests by different names, as ‘test for symmetry based on signed‐rank statistic’ and ‘test for median based on signed‐rank statistic’, respectively. The utility of such terminological differentiation should become evident through our discussion of how those tests connect and contrast with sign test and one‐sample t‐test. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.     

Victimization,Aggression, and Other Problem Behaviors: Trajectories of Change Within and Across Middle School Grades

This study examined trajectories of victimization and problem behaviors within and across three grades of middle school. Participants were 2,166 adolescents from three urban middle schools in the United States who completed measures of victimization, physical and relational aggression, substance use, and delinquent behavior. Latent curve analyses modeled changes in each construct across 12 waves collected every 3 months. In each case, the best‐fitting model required separate linear slopes to represent changes within each grade and a factor representing decreases in the summers. Positive cross‐construct correlations were found for intercepts, linear slopes, and measures within waves. The findings suggest strong associations among victimization and problem behaviors, and individual differences in their patterns of change both within and across grades.     

Measurement of Dating Aggression During Middle School: Structure,Measurement Invariance,and Distinction From General Aggression

Two studies examined the factor structure of a modified version of the Safe Dates dating aggression scale and evaluated whether dating aggression is distinct from general aggression during early adolescence. Analyses were conducted on a derivation sample of 3,894 adolescents from 37 schools (Study 1) and an independent cross‐validation sample of 938 middle school youth (Study 2). Categorical confirmatory factor analyses supported a two‐factor model (perpetration and victimization) over models differentiating psychological and physical forms of aggression. The model was invariant across time, sex, grade, and season. Study 2 also supported dating aggression as distinct from general aggression. Results supported measuring dating aggression perpetration and victimization as latent constructs represented by ordered categorical indicators that capture item severity and frequency.     

Is all well in the neighborhood? Conflict on neighborhood boards in Milwaukee

Neighborhood organizations have become more important players in urban areas in recent years due to a renewed interest in social capital and an emphasis on the continuing development of community. With this elevated status comes more responsibility for the delivery of services to citizens and scrutiny by these very citizens, the press, and government officials. Much of what we know about neighborhood organizations comes from our observations of board deliberations. Through these deliberations board members make decisions that affect neighborhood constituents. In this study we examine the context in which neighborhood boards in the city of Milwaukee, Wisconsin, make decisions. Using theory borrowed from the literature on local government boards, we develop a series of testable hypotheses relating to the level of conflict on these boards. Our findings indicate that conflict is relatively low across boards in Milwaukee; however, the number of board member and certain behavioral variables explain a significant amount of the variance in the level of conflict.     

Sexuality-Related Risks are Judged more Harshly than Comparable Health Risks

Objectives: In three studies, the authors examined the extent to which STIs and sexual behavior were perceived negatively compared to objectively riskier behaviors. Methods: In Study 1, participants estimated the risk of death as a result of contracting HIV from one instance of unprotected sex (with a noninjection drug user) relative to the risk of death as a result of an automobile accident (a 300 mile drive). In Study 2a, participants read one of two vignettes, in which a target either unknowingly transmitted an STI (chlamydia) or a nonsexual disease (H1N1) to another person through a sexual encounter. In Study 2b, participants read one of 12 vignettes; the type of disease (chlamydia or H1N1), severity of the disease outcome (mild, moderate, or severe), and sex of transmitter (female or male) were manipulated. In Study 3, state-level public health and driving websites were coded for risk-reduction recommendations. Results: In Studies 1 and 2, participants rated the target who transmitted chlamydia more negatively than the target who transmitted H1N1; participants also perceived the target who transmitted chlamydia with a mild severity outcome (the sexual partner took antibiotics for one week) more negatively than the target who transmitted H1N1 with a severe outcome (the sexual partner died from contracting H1N1; Study 2). In Study 3, most state-level public health websites promoted safety through a recommendation that the public abstain from sex; no similar recommendations were provided on driving websites (an objectively riskier behavior). Conclusions: The stigmatization of STIs is beyond the degree of severity (relative to other diseases) and viewed as unjustifiably risky (relative to other risky activities).     

Young Adults’ Race,Wealth, and Entrepreneurship

This study explored relationships among young adults’ wealth and entrepreneurial activities with emphasis on how these relationships differed among racial and ethnic groups. Using data from the 1997 National Longitudinal Survey of Youth, results indicated that young adults’ (N = 8984) higher accumulated amounts of wealth were associated with pursuing self-employment at higher rates; however, differences emerged when the associations were explored with various types of wealth and within racial and ethnic groups. Black young adults’ greater debt and net worth were associated with their increased likelihoods of self-employment. Among Latino/a young adults, greater liquid assets and net worth were associated with increased likelihoods of self-employment. Wealth was unrelated to white young adults’ self-employment. Wealth appeared to play an outsized role in the self-employment of black and Latino/a young adults compared to that of their white counterparts. In other words, racial and ethnic minority young adults may have a heavier burden for generating their own capital to embark on entrepreneurial activities when mainstream credit markets are unresponsive or inaccessible. Policy implications are discussed.     

Biological Research on Women's Sexual Orientations: Evaluating the Scientific Evidence

The importance of biological influences on sexual orientation is hotly debated. This article summarizes public opinions about the causes of sexual orientations and documents shifts over time toward greater endorsement of biological rather than environmental explanations. Next, empirical evidence concerning neuroendocrine and genetic explanations of women's sexual orientation is reviewed. Currently, there is no convincing evidence that biological factors are a determining influence on women's sexual orientations. In some research areas, the data on women are incomplete. In areas where adequate research is available, studies on women do not conclusively support biological hypotheses. Implications of these findings are considered.     

Attitudes, subjective experiences, and behaviors in imagined and actual encounters between gay and heterosexual people

Across four studies, we assessed the relationship between participants' attitudes toward gay men and their experiences during either imagined or actual interpersonal encounters with gay men. In the first three studies, participants imagined interactions with gay men and either responded in an open-ended or a closed-ended fashion. In these imagined interactions, participants reported that they expected to have considerable agreement between their attitudes and their subjective experiences during the intergroup encounter. However, during actual interactions, there were no differences between members of different prejudice levels in their responses to the gay confederate. A comparison of the actual and imagined interactions demonstrated that high prejudice people are particularly unlikely to have subjective experiences that match their negative attitudes concerning actual interpersonal encounters.