Becoming a physician: The influence of the undergraduate experience

This study employed a national sample of college students who initially aspired to be, or later became, physicians to determine the influence of precollege characteristics, college origins, and the academic and social experience of college on the likelihood of becoming a physician. Estimates of a 14-variable causal model indicated that the major direct effects on attainment were attributable to college characteristics and the academic experience of college. Net of other causes, the selectivity/prestige of the undergraduate institution attended, collegiate academic achievement, and majoring in the physical or life sciences each had significant direct effects on becoming a physician. The direct positive influence of college quality, however, was partially counterbalanced by its negative indirect effect. Moreover, the greatest advantage in attending an elite institution accrued to those students with relatively high levels of academic performance. As academic performance declined, so did the positive effect of college quality. The effects of precollege characteristics on becoming a physician were largely indirect, mediated by the student's college experience. Net of other factors, women were no less likely than men to become physicians, but being female had a significant negative indirect effect. Conversely, secondary school achievement did not directly influence attainment but did have a large positive indirect influence.An earlier version of this paper was presented at the annual meeting of the Association for the Study of Higher Education, San Diego, February, 1987.     

Maltreated children's developmental scores: treatment versus nontreatment

Following treatment in a therapeutic day treatment program, a group of 35 maltreated children were compared to a matched group of 35 maltreated children who had not been enrolled in a therapeutic day treatment program. The results of matched pairs t-test analyses indicated that the treatment subjects had significantly higher developmental scores in five areas of development--fine motor, cognitive, gross motor, social/emotional, and language. Further, pretest and posttest comparisons of the percentile scores of the treatment group indicated that the posttest scores were significantly higher than the pretest scores. This study demonstrates that remediation of developmental delays in maltreated children under the age of 6 years can be accomplished through an intensive day treatment program.     

Mathematics knowledge for understanding and problem solving

Two important aspects of transfer in mathematics learning are the application of mathematical knowledge to problem solving and the acquisition of more advanced concepts, both in mathematics and in other domains. This paper discusses general assumptions and themes of current cognitive research on mathematics learning, focusing on issues of the understanding thought to facilitate transfer of mathematical knowledge. Two studies illustrating these themes are presented, one concerning students' understanding of numerical relationships involved in basic addition and subtraction combinations, the other dealing with students' understanding of algebraic expressions and transformations. Implications of these cognitive perspectives for instruction are discussed.     

An incentive effect in thermally motivated behavior

Three shaved adult male albino rats were trained to press a lever to replace a hot air drive condition (50° C) with either a small reinforcer (32° C) or a large reinforcer (14° C). Following the 10-sec reinforcer, the drive condition was either reinstated immediately (no delay) or after a 15-sec exposure to the drive temperature, during which the bar was withdrawn (delay). Response rate during the no-delay procedure was faster for the small reinforcer than for the large. This relation reversed during the delay procedure. The former observation is similar to a satiation effect and the latter resembles an incentive effect.     

Hans Freudenthal (17 September 1905–13 October 1990)

Recorded are some biographical data about the late professor Freudenthal along with some indications about his mathematical work. In an appendix a tiny part of his mathematical work which can be explained in a fairly direct manner is discussed.This is the somewhat modified text of a commemorative address given at the annual meeting of the Wiskundig Genootschap, the Dutch mathematical society, on April 5, 1991, cf. Nieuw Archief voor Wiskunde, 9 (1991), 131–136.     

A content analysis of the presentation of the mole concept in chemistry textbooks

The goal of this study was to examine the means used by textbook authors to introduce, define, and explain the mole concept in high school and introductory college chemistry textbooks. The analysis was framed by four questions:

• 1 How is the mole defined?
• 2 What concepts about the atom are introduced prior to the mole?
• 3 Is Avogadro's constant presented as an experimentally determined value?
• 4 What is the context for introducing the mole?

Twenty-nine high school and introductory college level chemistry texts were examined. After independent reading of appropriate sections of each text, discussion of differences, second or third readings of texts, and subsequent discussions, both authors reach 100% agreement concerning the results. Major conclusions were

• 1 Two ways of defining the mole dominate the texts. One way defines the mole as Avogadro's number (6.02 × 10²³) particles; the other method defines the mole in terms of carbon-12.
• 2 All texts that present a definition in terms of C-12 introduce and define concepts about the atom prior to introducing the mole.
• 3 Most texts at all levels point out that the value 6.02 × 10²³ is an experimentally determined quantity.
• 4 Nearly all texts discuss the mole in relation to die problem of finding a way to count particles that are too small to be directly weighed. Most texts also use a familiar counting unit, such as the dozen, to introduce the mole by analogy.

Four issues were discussed: (a) the defining attributes of the mole concept itself and the cognitive requirements for comprehending the two most frequently used definitions; (b) the connection between the definition of the mole presented in the text and the concepts about atoms that are introduced before the mole concept is developed; (c) the experimental nature of Avogadro's number; and (d) the context or setting for developing the mole concept.