The central roles of science in the field of remedial and special education are to (a) identify basic laws of nature and (b) apply those laws in the design of practices that achieve socially valued outcomes. The scientific process is designed to allow demonstration of specific (typically positive) outcomes, and to assist in the attribution of…

This paper presents a non-parametric imputation technique, named random forest, from the machine learning field. The random forest procedure has two main tuning parameters: the number of trees grown in the prediction and the number of predictors used. Fifty experimental conditions were created in the imputation procedure, with different…

Recursive partitioning methods have become popular and widely used tools for nonparametric regression and classification in many scientific fields. Especially random forests, which can deal with large numbers of predictor variables even in the presence of complex interactions, have been applied successfully in genetics, clinical medicine, and…

In a well-designed experiment, random assignment of participants to treatments makes causal inference straightforward. However, if participants are not randomized (as in observational study, quasi-experiment, or nonequivalent control-group designs), group comparisons may be biased by confounders that influence both the outcome and the alleged…

It is of major importance to use psychological tests and questionnaires that are carefully constructed so that their reliability and validity can be determined in different (sub)cultures (Campbell & Tirri, 2004). However, a necessary prerequisite for this is the development of solid conceptual constructs. Otherwise, the researcher runs into the…

Attempts to provide evidence as to whether the oft-reported positive association between occupation and job satisfaction is independent of the effects of other variables, and to examine the effects of occupational prestige on the net occupation-job satisfaction relationship. (Author/RK)

Examines the effects of consensus information on the prediction of behavior as a function of social desirability of consensus information and the presence or absence of vignette information about target persons. Discusses the different manners in which consensus information can be used. (Author/RK)

In this paper, we explore the rules that determine intuitive predictions and judgments of confidence and contrast these rules to the normative principles of statistical prediction. (Author)

Research was conducted to investigate the phenomena associated with an individual's having perceived control or actual control over aversive stimuli. In all, 10 studies were conducted, 7 of which were directly relevant to investigating variables affecting perceived or actual control, and 3 being "spin-off" experiments. The seven studies…

The authors of "Differential Validity: Ethnic Group as a Moderator in Predicting Job Performance" (EJ 100 533) replied to criticism of their article by Wayne K. Kirchner (AA 521 804). (RK)

A study was conducted to establish an equation for predicting group embedded figures test (GEFT) scores using Comprehensive Tests of Basic Skills (CTBS) scores for reading and social studies, grade point averages, socioeconomic status, and student attitudes as predictor variables, and to determine correlation between these variables and the GEFT.…

Individual differences in academic success were investigated in a geographically defined whole-population sample of very preterm children with a gestational age of less than 32 weeks or a birth weight of less than 1500 gm. The sample consisted of 264 very preterm children (75.6% of German-speaking survivors) and 264 controls matched for gender,…