How Bias Reduction Is Affected by Covariate Choice,Unreliability, and Mode of Data Analysis: Results From Two Types of Within-Study Comparisons

This study uses within-study comparisons to assess the relative importance of covariate choice, unreliability in the measurement of these covariates, and whether regression or various forms of propensity score analysis are used to analyze the outcome data. Two of the within-study comparisons are of the four-arm type, and many more are of the three-arm type. To examine unreliability, simulations of differences in reliability are deliberately introduced into the 2 four-arm studies. Results are similar across the samples of studies reviewed with their wide range of non-experimental designs and topic areas. Covariate choice counts most, unreliability next most, and the mode of data analysis hardly matters at all. Unreliability has larger effects the more important a covariate is for bias reduction, but even so the very best covariates measured with a reliability of only .60 still do better than substantively poor covariates that are measured perfectly. Why regression methods do as well as propensity score methods used in several different ways is a mystery still because, in theory, propensity scores would seem to have a distinct advantage in many practical applications, especially those where functional forms are in doubt.     

Comments on “markovian processes with identifiable states: General considerations and applications to all-or-none learning”

When knowledge of the response sequence permits one to specify the sequence of theoretical states that occurred, we propose to say that the theory has observable states. Our earlier usage of identifiable conflicts with established usage in econometrics. We also present a revised definition of implication between theories that avoids a technical flaw in the earlier definition, and we correct a mistake in an example in our earlier paper.     

Electronic records of undesirable driving events

The cause of the majority of road crashes can be attributed to drivers’ behavior. Recent in-vehicle monitoring technologies enable continuous and high resolution measurements of drivers’ behaviors. We analyzed the information received from a novel in-vehicle technology which identifies the occurrences of undesirable driving events such as extreme braking and accelerating, sharp cornering and sudden lane changing. We undertook an exploratory analysis to provide better understanding of events frequency (EF) statistical properties. Our findings show higher EF in trip edges (trip beginning and trip end) than in the middle of the trip, higher EF for males than for females and higher EF at nighttime than at daytime. Use of the in-vehicle technology’s continuous and high resolution measurements enabled interesting advanced statistical analyses. Future research can use our findings to build similar statistical models to predict the occurrence of undesirable driving events by other independent variables.     

An application of DSM-IV's outline for cultural formulation: Understanding conduct disorder in Latino adolescents

In the established guidelines for providers of services to ethnic, linguistic, and culturally diverse populations, the American Psychological Association addressed the need for practitioners to consider the role that culture and ethnicity plays in the psychosocial development of culturally diverse populations. Currently, there are over 24 million Latinos in the United States, and this population is expected to quadruple in size to over 81 million in the year 2050. This discussion of a case example highlights the appropriateness of utilizing the outline for cultural formulation in working with Latino adolescents diagnosed with Conduct Disorder. As indicated by the DSM-IV's outline for cultural formulation, this discussion addresses the importance of assessing the following: 1) Cultural identity of the individual; 2) Cultural explanations of the individual's illness; 3) Cultural factors related to psychosocial environment and levels of functioning; 4) Cultural elements of the relationship between the individual and the clinician; 5) Overall cultural assessment for diagnosis and care. In particular, the discussion focuses on specific reasons why the utilization of the outline for cultural formulation can greatly assist the clinician in understanding many psychosocial elements unique to treating Conduct Disorder in the Latino adolescent.     

From structuralism to Marxism (and Back?): Jan Mukařovský 1945–1963

Studies in East European Thought - The paper covers the last phase of Jan Muka?ovský’s career between 1945 and 1964 during which his scholarly outlook underwent several steep...     

Clarification of the dual task dilemma: Lateralized effects for perfunctory and purposeful tasks in left- and right-handed males

The hypothesis that behavioral asymmetries with the dual task paradigm represent manual dominance was investigated with right- and left-handed males performing verbal and spatial tasks ordered by complexity. Lateralization was assessed for nonideational (perfunctory) and ideational (purposeful) components of tasks with multivariate and ANCOVA procedures. The outcomes of prerequisite tests showed the assumptions for conducting ANCOVA procedures were not satisfied with different handedness groups in the same design. However, results of the multivariate analyses suggest lateralized effects are more likely to represent the cognitive task when interference is high and may represent manual dominance when interference is low.     

Observing responses and uncertainty reduction. II The effect of varying the probability of reinforcement

The observing response paradigm was used to assess the reinforcing properties of discriminative stimuli by allowing animals either to work for food in the presence of a neutral stimulus or to first make an observing response by pressing a lever. On a progressive ratio schedule this resulted in the appearance of easily discriminable stimuli which marked positive and negative trials. The uncertainty associated with the imposed neutral stimulus was varied by manipulating the proportion of positive and negative trials in the session. The animals switched most often when the probability of reinforcement was low, less often when it was intermediate, and least often when it was high. This was not consistent with an uncertainty reduction hypothesis but could be explained if the uncertainty had to do with response rather than outcome.