Joseph M. Strayhorn

Randomized Trial of Methylphenidate for an Autistic Child

Abstract A single-case experiment testing the effectiveness of methylphenidate in a 6-year-old autistic boy was performed by randomly assigning treatment days to placebo or active drug, collecting daily blind ratings of behavior from the childs mother and from teachers, and statistically comparing the ratings for drug days with those for placebo days. Negative effects on mood and tantrums seemed to be outweighed by positive effects on attention and activity, destructive behavior, and stereotyped movements. This result fails to support past statements that stimulants are contraindicated with autistic children, and that stimulants do not reduce the hyperactivity of autistic children.

Chronological age at entrance to first grade: Effects on elementary school success

The effects of childrens ages at entrance to first grade upon success in elementary school was examined in a cohort of urban children who entered first grade in 1983. A set of demographic, social, and early experience variables was used as covariates in the analysis. Older children did slightly, but significantly better academically in first grade, primarily because of better performance in mathematics. There was no relationship between age of entrance and a measure of conduct in the first grade. Four years later, no effect of age at entrance to first grade upon academic performance or upon placement inside or outside the mainstream of regular education was found. Age at entrance was a far less powerful predictor than the socioeconomic variables in our covariate set.

Religiosity and teen birth rate in the United States.

BackgroundThe children of teen mothers have been reported to have higher rates of several unfavorable mental health outcomes. Past research suggests several possible mechanisms for an association between religiosity and teen birth rate in communities.MethodsThe present study compiled publicly accessible data on birth rates, conservative religious beliefs, income, and abortion rates in the U.S., aggregated at the state level. Data on teen birth rates and abortion originated from the Center for Disease Control; on income, from the U.S. Bureau of the Census, and on religious beliefs, from the U.S. Religious Landscape Survey carried out by the Pew Forum on Religion and Public Life. We computed correlations and partial correlations.ResultsIncreased religiosity in residents of states in the U.S. strongly predicted a higher teen birth rate, with r = 0.73 (p < 0.0005). Religiosity correlated negatively with median household income, with r = -0.66, and income correlated negatively with teen birth rate, with r = -0.63. But the correlation between religiosity and teen birth rate remained highly significant when income was controlled for via partial correlation: the partial correlation between religiosity and teen birth rate, controlling for income, was 0.53 (p < 0.0005). Abortion rate correlated negatively with religiosity, with r = -0.45, p = 0.002. However, the partial correlation between teen birth rate and religiosity remained high and significant when controlling for abortion rate (partial correlation = 0.68, p < 0.0005) and when controlling for both abortion rate and income (partial correlation = 0.54, p = 0.001).ConclusionWith data aggregated at the state level, conservative religious beliefs strongly predict U.S. teen birth rates, in a relationship that does not appear to be the result of confounding by income or abortion rates. One possible explanation for this relationship is that teens in more religious communities may be less likely to use contraception.

Martial arts as a mental health intervention for children? Evidence from the ECLS-K

BackgroundMartial arts studios for children market their services as providing mental health outcomes such as self-esteem, self-confidence, concentration, and self-discipline. It appears that many parents enroll their children in martial arts in hopes of obtaining such outcomes. The current study used the data from the Early Childhood Longitudinal Study, Kindergarten class of 1998-1999, to assess the effects of martial arts upon such outcomes as rated by classroom teachers.MethodsThe Early Childhood Longitudinal Study used a multistage probability sampling design to gather a sample representative of U.S. children attending kindergarten beginning 1998. We made use of data collected in the kindergarten, 3rd grade, and 5th grade years. Classroom behavior was measured by a rating scale completed by teachers; participation in martial arts was assessed as part of a parent interview. The four possible combinations of participation and nonparticipation in martial arts at time 1 and time 2 for each analysis were coded into three dichotomous variables; the set of three variables constituted the measure of participation studied through regression. Multiple regression was used to estimate the association between martial arts participation and change in classroom behavior from one measurement occasion to the next. The change from kindergarten to third grade was studied as a function of martial arts participation, and the analysis was replicated studying behavior change from third grade to fifth grade. Cohens f2 effect sizes were derived from these regressions.ResultsThe martial arts variable failed to show a statistically significant effect on behavior, in either of the regression analyses; in fact, the f2 effect size for martial arts was 0.000 for both analyses. The 95% confidence intervals for regression coefficients for martial arts variables have upper and lower bounds that are all close to zero. The analyses not only fail to reject the null hypothesis, but also render unlikely a population effect size that differs greatly from zero.ConclusionThe data from the ECLS-K fail to support enrolling children in martial arts to improve mental health outcomes as measured by classroom teachers.

Estimating the Errors Remaining in a Data Set: Techniques for Quality Control

Abstract This article presents two methods of quantifying the adequacy with which research data have been checked in the process of quality control. In the duplicate performance method, the data operation is carried out twice, independently, and the results are compared; the remaining errors in the data set can be estimated thereby and a confidence limit can be obtained. In the known errors method, the supervisor purposely introduces into a data set known errors similar in form to suspected unknown errors. Then a staff member checks the file; the results yield the number of known errors found and the number of unknown errors found. The method, like the duplicate performance method, allows the accuracy of both workers to be quantified and allows an estimate, with a confidence limit, of the number of as-yet-unfound errors still lurking in the data set.