Developmental priority of identity conservation: acceleration of identity and equivalence in normal and moderately retarded children

In an attempt to clarify the chronological relationship between identity and equivalence conservation, normal preschool-aged children (experiment 1) were exposed to brief videotape demonstrations of a model conserving identity and equivalence, identity only, equivalence only, or neither. Subsequent performances indicate that identity was easier to accelerate than equivalence, and training in both identity and equivalence appeared to be most effective in accelerating conservation. Trainable mentally retarded (TMR) children were then exposed to either the identity-equivalence-conserving or control model (experiment 2). This population, which some have argued remains at a preoperational level of functioning, was more likely to conserve identity than equivalence. In addition, conservation in the training group increased following training, though these gains were not maintained over a 3-week retention interval.     

Behavior of narcotics-addicted newborns.

The behavior of narcotics-addicted and nonaddicted newborns on the first 2 days of life was assessed with the Brazelton Neonatal Behavioral Assessment Scale. In addition to classic signs of narcotics abstinence, addicted infants were less able to be maintained in an alert state and less able to orient to auditory and visual stimuli. These deficits were especially pronounced at 48 hours of age. Addicted infants were as capable of self-quieting and responding to soothing intervention as normal neonates, although they were substantially more irritable. These characteristics and addicted infants' greater resistance to cuddling are discussed in terms of their potential impact on early infant-care-giver interaction.     

Definition in science teaching

Summary Definitions, I have suggested, have both a function and a form. The function pursued and the form used should depend on the situation and on the term being defined. In the situation described at the outset, Mr. Beta should probably have seen to it that a stipulation of some sort was given-just in order to get on with the task at hand. The stipulation might have been based upon a true reported definition-or it might not-depending on political considerations and the linguistic flexibility of the people concerned. Since no one involved could plausibly have been trying to embody a program in a definition of dough, a programmatic definition was not appropriate in that situation.Several different forms for a definition of dough might reasonably have been used, but in this case the old reliable classification form was probably best, because of its completeness, neatness, and brevity. Two reasonable alternatives are the equivalent-expression form and the range form. The synonym, example-nonexample, and operational forms were probably not appropriate.My main point is that there is not just one way to define. I hope that my delineation of some major possibilities and variations will help those who read this article to be flexible in handling problems of definition when they arise; and they arise more often than most people realize.An ealier draft of this article was presented at a colloquium at the University of Illinois in honor of Professor B. Othanel Smith at his retirement.     

Circular Plate on Multipoint Supports

Formulae are derived for the deflection surface of a symmetrically loaded circular plate having several points supports which are situated at equal distances apart on a single concentric circle. There is no restriction on the diameter of the support circle, which may be as large as the diameter of the plate itself. The results of this paper compare favorably with published experimental results. Numerical deflection coefficients for a uniformly loaded plate are provided, and these could be utilized for optimizing the positions and the number of concentrated supports.