The scientificalization of educational research methods was always the most predominant in the two tides of educational experiment in China in the twentieth century, the result of which was unexpectedly dissatisfactory, because researchers misunderstood the connotation of scientificalization in such a degree that resulted in the worship for…

Using meta-analysis, randomized experiments in education that either clearly did or clearly did not experience student attrition were examined for the baseline comparability of groups. Results from 35 studies suggested that after attrition, the observed measures of baseline comparability of groups did not differ more than would be expected given…

Explains the characteristics and importance of random assignment in experimental research on education. Considers factors supporting causal inferences, the nature of "assignment units," differences between random sampling and random assignment, the characteristics of randomization tests, forms of random assignment, and effects of experimental…

Discusses the size-weight illusion that occurs when a person lifts two equal-weight objects differing in size and perceives the larger object as lighter than the small object. Describes several inexpensive techniques for demonstrating the size-weight illusion and reviews some relevant issues concerning this phenomena. (MJP)

Maintains that having students estimate the size and width of a class waste paper can (placed on a desk) is a simple and effective way of illustrating perceptual distortion. Tests show that people will consistently overestimate the height of the can, allowing for a useful discussion on sensory distortion. (MJP)