This paper reviews the construction of an inexpensive motion tracking and data logging system, which can be used for a wide variety of teaching experiments ranging from entry-level physics courses to advanced courses. The system utilizes an affordable infrared camera found in a Nintendo Wiimote to track IR LEDs mounted to the objects to be…

Identifying the skills that determine the success or failure to exercises and question items is a difficult task. Multiple skills may be involved at various degree of importance, and skills may overlap and correlate. In an effort towards the goal of finding the skills behind a set of items, we investigate two techniques to determine the number of…

Often, in the case of experimental evaluations of multifaceted interventions, researchers and policymakers alike are interested in asking not only whether a given intervention had an effect but also why. They seek answers to questions such as: What features of the intervention led to the impacts that we have observed, or what was the causal…

Conventional wisdom suggests that inhalant use is primarily isolated to youthful experimentation; however, a growing body of evidence suggests that inhalant use (a) occurs after use of common substances of experimentation (e.g., alcohol, marijuana), (b) can persist into later life, and (c) is associated with severe consequences. The current study…

This article discusses two "magic tricks" in terms of underlying optical principles. The first trick is new and produces a "ghost" in the air, and the second is the classical real image produced with two parabolic mirrors. (Contains 2 figure and 6 photos.)

Transcription termination comes in two forms in "E. coli" cells. Rho-dependent termination requires the binding of a termination protein called Rho factor to the transcriptional machinery at the terminator region, whereas Rho-independent termination is achieved by conformational changes in the transcript itself. This article presents a test…

Stimuli that precede aversive events are typically less preferred than stimuli that precede nonaversive events. It has recently been demonstrated that stimuli that "follow" less preferred events may become favored more than stimuli that follow more preferred events. This phenomenon has been investigated under a variety of names, most commonly,…

The target paper by Barba (2012) raises issues that were the focus of the author's first two publications on operant variability. The author will describe the main findings in those papers and then discuss Barba's specific arguments. Barba has argued against the operant nature of variability. (Contains 2 figures.)

We conducted a haptic search experiment to investigate the influence of the Gestalt principles of proximity, similarity, and good continuation. We expected faster search when the distractors could be grouped. We chose edges at different orientations as stimuli because they are processed similarly in the haptic and visual modality. We therefore…

There is a general debate as to whether constituent representations are accessed in compound processing. The present study addresses this issue, exploiting the properties of Italian compounds to test the role of headedness and semantic transparency in constituent access. In a first experiment, a lexical decision task was run on nominal compounds.…

The revelation effect is a change in response behavior induced by a preceding problem-solving task. Previous studies have shown a revelation effect for faces when the problem-solving task includes attractiveness ratings of the faces. Immediately after this problem-solving task participants judged faces as more familiar than without the…

Does retrieval practice produce learning because it is an especially effective way to induce elaborative encoding? Four experiments examined this question. Subjects learned word pairs across alternating study and recall periods, and once an item was recalled it was dropped from further practice, repeatedly studied, or repeatedly retrieved on…

What does it mean to compare sets of objects along a scale, for example by saying "the men are taller than the women"? We explore comparison of pluralities in two experiments, eliciting comparison judgments while varying the properties of the members of each set. We find that a plurality is judged as "bigger" when the mean size of its members is…

The inspiration for this paper comes from a successful experiment conducted with students in the "Mobile Robots" course in the fifth year of the integrated Master's program in the Department of Electrical and Computer Engineering, Faculty of Engineering, University of Porto (FEUP), Porto, Portugal. One of the topics in this Mobile Robots…

Aim: We aimed to explore the organization of the calendar knowledge base underlying date calculation by assessing the ability of savant calendar calculators to free recall a series of date lists. Method: Four experiments are reported that assessed recall of structural and non-structural features of the calendar in eight savant calendar calculators…