This article reviews the origins and use of the terms quasi-experiment and natural experiment. It demonstrates how the terms conflate whether variation in the independent variable of interest falls short of random with whether researchers find, rather than intervene to create, that variation. Using the lens of assignment--the process driving…

This article seeks to provide researchers and practitioners in laboratory education, particularly those involved in the curriculum design and implementation of teaching laboratories at university level, with a conceptual framework and a working model for an integrated assessment of learning domains, by attending to a more holistic approach to…

Described is a school project to investigate aggregations in flatworms which may be influenced by light intensity, temperature, and some form of chemical stimulus released by already aggregating flatworms. Such investigations could be adopted to suit many educational levels of science laboratory activities. (DS)

Describes an apparatus for an experiment on winding motion in three dimensions. Discusses theory and provides a calculation example. (JM)

Describes a relatively simple method of extraction and purification of bacterial DNA. This technique permits advanced secondary-level science students to obtain adequate amounts of DNA from very small pellets of bacteria and to observe some of its polymer properties. (ML)

Describes a laboratory experiment to teach the principles of air sampling, gamma ray spectroscopy, nuclear decay, and radioactive equilibrium. Analyzes radon by carbon adsorption and gamma ray counting. Provides methodology and rate of decay equations. (MVL)

Discusses when alternating and magnetic fields are independent. Provides examples of experiments involving mains hum and the detection of induced signals. Describes electric circuits and oscilloscope displays. (Author/YP)

Describes some experiments for investigating the speed of atomic gas beams and displaying their atomic character. Discusses the experimental apparatus and the time-of-flight method. (YP)

Examines the thermal decomposition of sodium bicarbonate to sodium carbonate. Encourages students to predict the end products and to use the stoichiometric results to determine if their predictions are correct. (MVL)

Describes a laboratory experiment which focuses on the importance of water in germination and seedling emergence. Discusses the activity's design, expected results, and possible application. Offers suggestions for extending the experiment. (ML)

The Prime Minister's Committee on Natural Science in Education in Great Britain reported in 1918 that "...in many schools more time is spent in laboratory work than the results obtained can justify." Seventy years later this conclusion can often still be drawn. This is particularly a problem in open distance education where laboratory practicals,…

Argues that computer-simulated experiments offer educational tools to foster student development of problem-solving skills without traditional laboratory time and expense. The evolution of the medical physiology course at Rush Medical College is used to illustrate trends in this area. They include experiments on PLATO, and on personal computers.…

Describes two quantitatively-oriented physiology laboratories for veterinary students. The laboratory exercises incorporate the procedures of radiology and physical examination with measurement of pulmonary function. Specific laboratory objectives, procedures and equipment needed for diagnoses of the pathologies are listed. (ML)

Describes methods for studying the direct effect of thyroid hormones on the induction of metamorphic change in amphibians. (CS)

Discusses the change in pressure as a balloon expands. Describes the pressure change in a spherical soap bubble and a rubber membrane on the tube. Provides demonstrations when two balloons are connected by a tube. Lists five further reading materials. (YP)