The study explores if established support devices for paper-pencil problem solving, namely worked examples and incremental scaffolds, are applicable to laboratory tasks. N?=?173 grade eight students solved in dyads a physics laboratory task in one of three conditions. In condition A (unguided problem solving), students were asked to determine the…

A different method to study the charging and discharging processes of a capacitor is presented. The method only requires a high impedance voltmeter. The charging and discharging processes of a capacitor are usually studied experimentally using an oscilloscope and, therefore, both processes are studied as a function of time. The approach presented…

The terms "concreteness fading" and "progressive formalization" have been used to describe instructional approaches to science and mathematics that use grounded representations to introduce concepts and later transition to more formal representations of the same concepts. There are both theoretical and empirical reasons to…

This article describes a computational project designed for undergraduate students as an introduction to mathematical modeling. Students use an ordinary differential equation to describe fish weight and assume the instantaneous growth rate depends on the concentration of dissolved oxygen. Published laboratory experiments suggest that continuous…

Two studies examined the effects of university students' achievement goals on performance under low versus high challenge conditions. The first was a laboratory experiment in which participants were assigned goals to pursue on a novel mathematics task alleged to be simple or complex to use. The second was a survey study in which students set goals…

As a result of the use of random assignment to treatment, randomized experiments typically have high internal validity. However, units are very rarely randomly selected from a well-defined population of interest into an experiment; this results in low external validity. Under nonrandom sampling, this means that the estimate of the sample average…

We present "Xipx," the first port of a major educational operating system to a processor in the emerging class of many-core architectures. Through extensions to the proven Embedded Xinu operating system, Xipx gives students hands-on experience with system programming in a distributed message-passing environment. We expose the software primitives…

An upper-division instrumental chemistry laboratory has been developed in which students use atomic force microscopy (AFM) to collect force curves on polydimethylsiloxane (PDMS) elastomers. Force curves are used to quantify the stiffness of elastomers prepared with different base-to-curing agent ratios. Trends in observed spring constants of the…

An undergraduate laboratory exercise is described to demonstrate the biochemical applications of electron paramagnetic resonance (EPR) spectroscopy. The beta93 cysteine residue of hemoglobin is labeled by the covalent binding of 3-maleimido-proxyl (5-MSL) and 2,2,5,5-tetramethyl-1-oxyl-3-methyl methanethiosulfonate (MTSL), respectively. The excess…

The essential oil of "Nepeta cataria" L. (catnip), an herbaceous plant known popularly as a stimulant for the domestic cat, is enriched in two diastereomeric iridoid lactones (nepetalactones) that vary in ratio. Although the diastereomers are chromatographically separable and exhibit different 1D NMR spectra, it is not possible to…

Production of thin metal oxide films was recently explored as part of an outreach program with a goal of producing nanoscale structures with household items. Household items coated with various metals or titanium compounds can be heated to produce colorful films with nanoscale thicknesses. As part of a materials chemistry laboratory experiment…

An undergraduate exercise in computational chemistry that investigates the energy barrier for pyramidal inversion of amines and phosphines is presented. Semiempirical calculations (PM3) of the ground-state and transition-state energies for NR[superscript 1]R[superscript 2]R[superscript 3] and PR[superscript 1]R[superscript 2]R[superscript 3] allow…

Modern undergraduate organic chemistry textbooks provide detailed discussion of stoichiometric Cr- and Mn-based reagents for the oxidation of alcohols, yet the use of such oxidants in instructional and research laboratories, as well as industrial chemistry, is increasingly avoided. This work describes a laboratory exercise that uses ambient air as…

To date, the nature of the phonological deficit in developmental dyslexia is still debated. We concur with possible impairments in the representations of the universal phonological constraints that universally govern how phonemes co-occur as a source of this deficit. We were interested in whether-and how-dyslexic children have sensitivity to…

People often displace their anger and aggression against innocent targets, sometimes called scapegoats. Tragic historic events suggest that members of ethnic minority out-groups may be especially likely to be innocent targets. The current experiment examined displaced aggression of Dutch youths against Dutch in-group peers versus Moroccan…