We examine the impact of remedial and developmental courses on college students with varying levels of academic preparedness, thus focusing on a wider range of students than previous studies. Using a regression discontinuity design, we provide causal estimates of the effects of placement in different levels of remedial courses on short-,…

The goal of this study was to determine if typically developing children could form grammatical categories from distributional information alone. Twenty-seven children aged six to nine listened to an artifcial grammar which contained strategic gaps in its distribution. At test, we compared how children rated novel sentences that ft the grammar to…

To test the hypothesis that a higher tendency to "s"pontaneously "f"ocus "o"n "m"ultiplicative "r"elations (SFOR) leads to improvements in rational number knowledge via more exact estimation of fractional quantities, we presented sixth graders (n = 112) with fraction number line estimations and a…

Hypothesis generation is an important but difficult process for students. This study investigated the effects of providing students with support for hypothesis generation, with regard to the testability and complexity of the generated hypotheses, the quality of the subsequent inquiry learning processes and knowledge acquisition. Fifty-two…

M-fluctuation tests are a recently proposed method for detecting differential item functioning in Rasch models. This article discusses a generalization of this method to two additional item response theory models: the two-parametric logistic model and the three-parametric logistic model with a common guessing parameter. The Type I error rate and…

When a psychologist announces a new research finding, it is often based on a rejected null hypothesis. However, if that hypothesis is true, the claim is a false alarm. Many students mistakenly believe that the probability of committing a false alarm equals alpha, the criterion for statistical significance, which is typically set at 5%. Instructors…

Object-based learning is an approach that aims to foster observational skills and sensory awareness. Paradoxical plant objects that do not lend themselves to all-too-easy explanations and interpretations can be used to practice the search for ecological explanations and the formation of evolutionary hypotheses. They can be the basis of…

When comparing social science phenomena through a time perspective, absolute and relative difference (RD) are the two typical presentation formats used to communicate interpretations to the audience, while time distance (TD) is the least frequently used of such formats. This article argues that the chosen presentation format is extremely important…

This dissertation investigated how four factors -- the degree of L2 experience, L1 sound structure, age difference in L1 language development and age of L2 exposure -- affect the perceptual cue weighting of duration and spectral differences for English tense-lax vowel contrasts. Four major hypotheses were tested: desensitization hypothesis (DH)…

People tend to show better memory for information that is deemed valuable or important. By one mechanism, individuals selectively engage deeper, semantic encoding strategies for high value items (Cohen, Rissman, Suthana, Castel, & Knowlton, 2014). By another mechanism, information paired with value or reward is automatically strengthened in…

For the two-way factorial design in analysis of variance, the current article explicates and compares three methods for controlling the Type I error rate for all possible simple interaction contrasts following a statistically significant interaction, including a proposed modification to the Bonferroni procedure that increases the power of…

This article considers the nature and place of tests of statistical significance (ToSS) in science, with particular reference to psychology. Despite the enormous amount of attention given to this topic, psychology's understanding of ToSS remains deficient. The major problem stems from a widespread and uncritical acceptance of null hypothesis…

Metatheoretical perspectives, and their role in influencing the research process, can be difficult for undergraduate students to grasp. The communication field brings together myriad approaches to communication, lending to students' confusion (Muller, H. L., & Craig, R. T. [2007]. Introduction. In R. T. Craig & H. L. Muller [Eds.],…

This study explored the hypothesis that preschoolers' deductive reasoning would be improved by encouraging use of divergent thinking (DT). Children of 4-5 years of age (n = 120) were randomly given DT or neutral control exercises before deductive reasoning problems. To allow a stronger test of the hypothesis, half of the children receiving the DT…

Professional development for teachers is regarded as one of the principal pathways through which we can understand and cultivate effective teaching and improve student outcomes. A critical component of studies that seek to improve teaching through professional development is the detailed assessment of the intermediate teacher development processes…