So-called "Color Wonder" markers contain colorless dyes that only display color when used to mark on special "Color Wonder" paper. These markers make use of leuco dyes that only develop color in the presence of acid. These markers provide science educators with a novel chemical system that can be implemented in inquiry-based…

For researchers seeking to improve education, a common goal is to identify teaching practices that have causal benefits in classroom settings. To test whether an instructional practice exerts a causal influence on an outcome measure, the most straightforward and compelling method is to conduct an experiment. While experimentation is common in…

This paper reviews the use of multiple trials, defined as multiple sites or multiple arms in a single evaluation and replications, in evaluating social programs. After defining key terms, the paper discusses the rationales for conducting multiple trials, which include increasing sample size to increase statistical power; identifying the most…

The work describes an analogy-based small oscillations analysis of a standard static equilibrium lab problem. In addition to force analysis, a potential energy function for the system is developed, and by drawing out mathematical similarities to the simple harmonic oscillator, we are able to describe (and experimentally verify) the period of small…

A recent note in this journal presented a demonstration of standing waves along a cord consisting of two parts having different material densities, showing different sized wavelengths in each part. A generalization of that experiment to a continuously varying linear mass density is to vibrate a strip of material with gradually varying width (mass…

Special events like science days, teacher's meetings and physics recruiting efforts require spectacular and, if possible, interactive experiments for the audience. Based on past experience with such events, we have gathered and present here a series of demonstration experiments in mechanics, optics, waves and electricity which are suitable, and…

Community college stakeholders are searching with increasing urgency for approaches with the potential to improve the success rates for community college students, particularly those in need of developmental education. "Learning communities," which place cohorts of students together in two or more courses for one semester, are a popular…

Although random assignment is generally the preferred methodology in impact evaluations, it raises numerous ethical concerns, some of which are addressed by securing participants' informed consent. However, there has been little investigation of how consent is obtained in social experiments and the amount of information that can be conveyed--and…