Although diffusion is the subject of beginning chemistry classes, there are a variety of experiments, such as the spread of perfume in the classroom, that are often "incorrectly" explained by diffusion alone. To eliminate this common misconception, a recently published method is modified to determine the diffusion constant of hydrogen…

In particular research domains, the randomized control trial (RCT) is considered to be the only means for obtaining reliable estimates of the true impact of an intervention. However, an RCT design would often not be considered ethical, politically feasible, or appropriate for evaluating the impact of many policy, programme, or structural changes…

We argue that the nativist-empiricist debate in developmental psychology is distorted, both theoretically and methodologically, by a shared framework of assumptions concerning the nature of representation. In particular, both sides of the debate assume models of representation that make the emergence of representation impossible. This, in turn,…

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…

A simple electronic system for the measurement of high values of resistance is shown. This system allows the measurement of resistance in the range of a few megohm up to 10[superscript 9] [omega]. We have used this system for the evaluation of CdS thin film resistance, but other practical uses in the basic physics laboratory are presented.…

We present a sensitive diffusion cloud chamber which does not require any radioactive sources. A major difference from commonly used chambers is the use of a heat sink as its bottom plate. The result of a performance test of the chamber is given. (Contains 8 figures.)

We propose and evaluate a memory-based model of Hick's law, the approximately linear increase in choice reaction time with the logarithm of set size (the number of stimulus-response alternatives). According to the model, Hick's law reflects a combination of associative interference during retrieval from declarative memory and occasional savings…

Education is an ever-changing field, yet constants remain: A teacher must be able to motivate students to become lifelong learners. Science has much to offer--the excitement that comes from discovery and learning can carry over into adulthood. Science provides an avenue for students to encounter phenomena in their environment and to discover…

Automatics and Robotics subjects are always greatly improved when classroom teaching is supported by adequate laboratory courses and experiments following the "learning by doing" paradigm, which provides students a deep understanding of theoretical lessons. However, expensive equipment and limited time prevent teachers having sufficient…

This paper describes a heat-transfer experiment that combines steady-state analysis and dynamic control. A process-water stream is circulated through two tube-in-shell heat exchangers in series. In the first, the process water is heated by steam. In the second, it is cooled by cooling water. The equipment is pilot-plant size: heat-transfer areas…

Working with evidence is a fundamental part of scientific enquiry. Children should be taught to consider evidence and evaluate it. They should make simple comparisons, comparing what happened with what they expected to happen, and try to explain what happened through drawing on their knowledge and understanding. In this article, the author…

This article discusses CALL development from both educational and ergonomic perspectives. It focuses on the learner-task-tool interaction, in particular on the aspects contributing to its overall quality, herein called "usability." Two pilot studies are described that were carried out with intermediate to advanced learners of French in two…

This paper is based upon experiments developed as part of a Directed Research course designed to provide undergraduate biology students experience in the principles and processes of the scientific method used in biological research. The project involved the evaluation of herbal remedies used in many parts of the world in the treatment of diseases…

Instruction is increasingly being delivered through distributed multimedia applications. Instruction delivered through these online environments creates robust opportunities for content presentation and learner interaction. These environments give the designer control over every aspect of the instructional experience. With some simple…

A classroom exercise for undergraduate and beginning graduate students that takes about one class period is proposed and discussed. It is an easy, interesting exercise that demonstrates important aspects of sampling techniques (sample amount, particle size, and the representativeness of the sample in relation to the bulk material). The exercise…