In this article, the authors consider the possibility that groups could be different, because of the different conditions of a factor. This is as far as the analysis can extend: the consideration is restricted to groups characterized by the different category of the factor being considered. In many biological experiments, the factor considered may…

Infants can track small groups of solid objects, and infants can respond when these quantities change. But earlier work is equivocal about whether infants can track continuous substances, such as piles of sand. Experiment 1 ("N" = 88) used a habituation paradigm to show infants can register changes in the size of piles of sand that they…

The present study aimed to investigate whether perceptual completion is available at birth, in the absence of any visual experience. An extremely underspecified kinetic visual display composed of four spatially separated fragments arranged to give rise to an illusory rectangle that occluded a vertical rod (illusory condition) or rotated so as not…

Educational versions of Millikan's oil-drop experiment have frequently been criticized; suggestions for improvement either focus on technical innovations of the setup or on replacing the experiment by other approaches of familiarization, such as computer simulations. In our approach, we have analysed experimental procedures. In doing so, we were…

Presents the results of an experiment designed to test two hypotheses: (1) a delay of two weeks at room temperature will have no effect on the viability of fertile chicken eggs and (2) refrigeration will have no effect on the viability of fertile chicken eggs. Experimenters were the author and two ninth-grade students. (PEB)

Presents a criminalistics laboratory experiment of benzidine rearrangement and the detection of trace quantities of blood which does not utilize carcinogens. (SL)

Stefan's law is demonstrated by measuring the temperature of the tungsten filament of an electric light bulb and plotting a log-log graph of temperature against power dissipation. (MLH)

Describes an experiment which allows students to observe the four oxidation states of vanadium obtained in aqueous solution. (SL)

Describes experiments conducted with semiconductors, photo-cells, and an oscilloscope. (SL)

Describes an experiment for determining the acceleration of a projectile. (SL)

Describes an experimental arrangement which provides a simple introduction to holographic interferometry. (SL)

Presents simple and inexpensive demonstrations of properties of metallic glasses. (SL)

Describes a microbiological experiment designed to study the competition between two species of bacteria. Experimental procedures and data obtained in conducting this experiment are provided, together with a discussion of the results. (JR)