Distribution-free tests of stochastic dominance for small samples

One variable is said to “stochastically dominate” another if the probability of observations smaller than x is greater for one variable than the other, for all x. Inferring stochastic dominance from data samples is important for many applications of econometrics and experimental psychology, but little is known about the performance of existing inferential methods. Through simulation, we show that three of the most widely used inferential methods are inadequate for use in small samples of the size commonly encountered in many applications (up to 400 observations from each distribution). We develop two new inferential methods that perform very well in a limited, but practically important, case where the two variables are guaranteed not to be equal in distribution. We also show that extensions of these new methods, and an improved version of an existing method, perform quite well in the original, unlimited case.     

Estimating and testing autocorrelation with small samples: A comparison of the c-statistic to a modified estimator

Huitema and McKean (Psychological Bulletin, 110, 291–304, 1991) recently showed, in a Monte-Carlo study, that five conventional estimators of first-order autocorrelation perform poorly for small (< 50) sample sizes. They suggested a modified estimator and a test for autocorrelation. We examine an estimator not considered by Huitema and McKean: the C-statistic (Young, Annals of Mathematical Statistics, 12, 293–300, 1941). A Monte-Carlo study of the small sample properties of the C-statistic shows that it performs as well or better than the modified estimator suggested by Huitema and McKean (1991). The C-statistic is also shown to be closely related to the d-statistic of the widely used Durbin-Watson test.     

Maximum likelihood estimation of the joint covariance matrix for sections of tests given to distinct samples with application to test equating

Consider an old testX consisting ofs sections and two new testsY andZ similar toX consisting ofp andq sections respectively. All subjects are given testX plus two variable sections from either testY orZ. Different pairings of variable sections are given to each subsample of subjects. We present a method of estimating the covariance matrix of the combined test (X ₁, ...,X _s ,Y ₁, ...,Y _p ,Z ₁, ...,Z _q ) and describe an application of these estimation techniques to linear, observed-score, test equating.The author is indebted to Paul W. Holland and Donald B. Rubin for their encouragement and many helpful comments and suggestions that contributed significantly to the development of this paper.This research was supported by the Program Statistics Research Project of the ETS Research Statistics Group.     

The association of ecological variables and psychological distress with exposure to community violence among adolescents

Ecological theory suggests that exposure to community violence should be related to individual, family, and community characteristics; traumatic stress theory suggests that exposure to community violence should be related to level of psychological distress. A correlational study of 468 older adolescents in New York City tested these hypotheses. Exposure was found to be moderately related to level of psychological distress, but was not related to family or neighborhood characteristics. It was concluded that the nature of exposure to community violence poses difficulties for interventions aimed at either prevention or amelioration of effects.     

A central limit theorem for families of stochastic processes indexed by a small average step size parameter,and some applications to learning models

Let > 0 be a measure of the average step size of a stochastic process {p _n ⁽⁾ } _n=1 ⁽⁾. Conditions are given under whichp _n ⁽⁾ is approximately normally distributed whenn is large and is small. This result is applied to a number of learning models where is a learning rate parameter andp _n ⁽⁾ is the probability that the subject makes a certain response on thenth experimental trial. Both linear and stimulus sampling models are considered.     

Comparing Group-Contingency and Individualized Equivalence-Based Instruction to a PowerPoint Lecture to Establish Equivalence Classes of Reinforcement and Punishment Procedures with College Students

The Psychological Record - Equivalence-based instruction (EBI) involves the teaching of socially relevant material (e.g., academic material) with stimulus equivalence procedures. In the research...     

Comparison of simultaneous prompting and constant time delay procedures in teaching sight words to elementary students with moderate mental retardation

Simultaneous prompting (a type of antecedent prompt and test procedure) and constant time delay were compared with four students with moderate mental retardation learning expressive sight words. A parallel treatments design across word sets and replicated across students was used. For acquisition, the simultaneous prompting procedures required fewer trials, sessions, and training time to criterion and resulted in fewer student errors during daily probe and training sessions. However, maintenance data indicated mixed results across the two procedures. Reliability data (both dependent and independent variables) revealed no differences between the two procedures in terms of the teacher's accuracy in recording student responses and implementing each procedure. Future research issues are discussed.     

Delayed matching to two-picture samples by individuals with and without disabilities: an analysis of the role of naming

Delayed matching to complex, two-picture samples (e.g., cat-dog) may be improved when the samples occasion differential verbal behavior. In Experiment 1, individuals with mental retardation matched picture comparisons to identical single-picture samples or to two-picture samples, one of which was identical to a comparison. Accuracy scores were typically high on single-picture trials under both simultaneous and delayed matching conditions. Scores on two-picture trials were also high during the simultaneous condition but were lower during the delay condition. However, scores improved on delayed two-picture trials when each of the sample pictures was named aloud before comparison responding. Experiment 2 replicated these results with preschoolers with typical development and a youth with mental retardation. Sample naming also improved the preschoolers' matching when the samples were pairs of spoken names and the correct comparison picture matched one of the names. Collectively, the participants could produce the verbal behavior that might have improved performance, but typically did not do so unless the procedure required it. The success of the naming intervention recommends it for improving the observing and remembering of multiple elements of complex instructional stimuli.     

Specificity of peer difficulties to social anxiety in early adolescence: categorical and dimensional analyses with clinical and community samples

Background and Objectives: We investigated the specificity of social difficulties to social anxiety by testing associations of social anxiety and other anxiety presentations with peer acceptance and victimization in community and treatment-seeking samples of adolescents aged 12–14 years.

Design: Cross-sectional, quantitative survey.

Methods: Adolescents from the community (n?=?116) and a clinical setting (n?=?154) completed ratings of anxiety symptoms, perceived social acceptance, and peer victimization. Their parents also completed ratings of the adolescents’ anxiety and social acceptance.

Results: Social acceptance was lowest among adolescents with social anxiety disorder (SAD) and lower among adolescents with other anxiety disorders than in the community sample. Anxiety symptoms were negatively correlated with social acceptance, but these associations were not unique to social anxiety symptoms. Girls in the community sample reported more overt victimization than girls with SAD and with other anxiety diagnoses. Relational victimization was associated with social and nonsocial anxiety symptoms only in the community sample.

Conclusions: Our findings supplement recent laboratory-based observational studies on social functioning among adolescents with SAD and other anxiety disorders. Although social anxiety may be associated with unique social skill deficits and impairment, concerns about peer relations should also be considered among adolescents with other anxiety symptoms.     

The role of social and dispositional variables associated with emotional processing in adjustment to breast cancer: an internet-based study.

Cognitive and emotional processing is seen as critical to successful adjustment to traumatic experiences, such as breast cancer. Cognitive and emotional processing can be facilitated by dispositional and social environmental factors. Emotional intelligence is a dispositional characteristic defined as the ability to understand, accurately perceive, express, and regulate emotions (J. D. Mayer & P. Salovey. 1997). This study investigated psychological adjustment as a function of emotional intelligence, social support, and social constraints in 210 patients recruited via postings to Internet-based breast cancer support groups. Regression analyses indicated high social constraints and low emotional intelligence were associated with greater distress. Evidence suggested high emotional intelligence could buffer against the negative impact of a toxic social environment. Results support a social-cognitive processing model of adaptation to traumatic events and suggest consideration of emotional intelligence may broaden this model.     

A generalization of the Yule-Simon model,with special reference to word association tests and neural cell assembly formation

A generalization of the Yule-Simon model is suggested and such related questions as inversion problems and nonequilibrium behavior are solved. The generalization follows the work of Haight and Jones (Journal of Mathematical Psychology, 1974, 11, 237–244) and thus special reference is made to word association tests. Some new possible applications of the presented model are offered, namely, in the field of neural cell assemblies.     

The relationship between parental report on the BRIEF and performance-based measures of executive function in children with moderate to severe traumatic brain injury.

The Behavior Rating Inventory of Executive Function (BRIEF) is a questionnaire that assesses parental observations of behaviors associated with executive function in children in the home environment. The current investigation examines the relationship between the BRIEF and individually-administered neuropsychological tests in children with traumatic brain injury. Forty-eight children with moderate to severe traumatic brain injury were administered the WISC-III and several performance-based tests of executive function (the Wisconsin Card Sorting Test, Trail Making Test Part B, verbal fluency), and a parent completed the BRIEF. Results indicate that the Metacognition Index from the BRIEF correlates with Verbal IQ, but none of the index scores from the BRIEF correlate with any of the performance-based tests of executive function. Results are discussed with respect to the ecological validity of standardized clinical neuropsychological tests of executive function.     

Social cognition and real-life functioning in patient samples with 22q11.2 deletion syndrome with or without psychosis,compared to a large sample of patients with schizophrenia only and healthy controls

Patients with the 22q11.2 deletion syndrome (DS) show an increased risk of developing a psychotic illness lifetime. 22q11.2DS may represent a reliable model for studying the neurobiological underpinnings of schizophrenia. The study of social inference abilities in a genetic condition at high risk for psychosis, like 22q11.2DS, may shed light on the relationships between neurocognitive processes and patients' daily general functioning. The study sample consisted of 1736 participants, divided into four groups: 22q11.2DS patients with diagnosis of psychotic disorder (DEL SCZ, N = 20); 22q11.2DS subjects with no diagnosis of psychosis (DEL, N = 43); patients diagnosed with schizophrenia without 22q11.2DS (SCZ, N = 893); and healthy controls (HC, N = 780). Social cognition was assessed through The Awareness of Social Inference Test (TASIT) and general functioning through the Specific Levels of Functioning (SLoF) scale. We analysed data through regression analysis. The SCZ and DEL groups had similar levels of global functioning; they both had significantly lower SLoF Total scores than HC (p < .001); the DEL SCZ group showed significantly lower scores compared to the other groups (SCZ, p = .004; DEL, p = .003; HC, p < .001). A significant deficit in social cognition was observed in the three clinical groups. In the DEL SCZ and SCZ groups, TASIT scores significantly predicted global functioning (p < .05). Our findings of social cognition deficit in psychosis-prone patients point to the possible future adoption of rehabilitation programmes, like Social Skills Training and Cognitive Remediation, during premorbid stages of psychosis.     

Tapping in synchrony with a perturbed metronome: the phase correction response to small and large phase shifts as a function of tempo

When tapping is paced by an auditory sequence containing small phase shift (PS) perturbations, the phase correction response (PCR) of the tap following a PS increases with the baseline interonset interval (IOI), leading eventually to overcorrection (B. H. Repp, 2008). Experiment 1 shows that this holds even for fixed-size PSs that become imperceptible as the IOI increases (here, from 400 to 1200 ms). Earlier research has also shown (but only for IOI=500 ms) that the PCR is proportionally smaller for large than for small PSs (B. H. Repp, 2002a, 2002b). Experiment 2 introduced large PSs and found smaller PCRs than in Experiment 1, at all of the same IOIs. In Experiments 3A and 3B, the author investigated whether the change in slope of the sigmoid function relating PCR and PS magnitudes occurs at a fixed absolute or relative PS magnitude across different IOIs (600, 1000, 1400 ms). The results suggest no clear answer; the exact shape of the function may depend on the range of PSs used in an experiment. Experiment 4 examined the PCR in the IOI range from 1000 to 2000 ms and found overcorrection throughout, but with the PCR increasing much more gradually than in Experiment 1. These results provide important new information about the phase correction process and pose challenges for models of sensorimotor synchronization, which presently cannot explain nonlinear PCR functions and overcorrection.