Discovering the Laws of Sampling

That the sample mean and variance are “good” estimates of the corresponding population parameters is easily accepted as “obvious” by students, but the concept of standard error of the mean is often found to be quite a hurdle. That this standard error decreases inversely as the square-root of the sample size, and the mysterious appearance of the Normal distribution, are often taken as magical and incomprehensible effects, and non-mathematical students can often be turned away from further understanding. This article describes a program which provides an experimental framework in which the student can rapidly develop an intuition for the basic properties of sampling.     

The nexus between college choice and persistence

Initial student commitments have long been considered an influence on persistence, but the reasons why students choose to attend a college have seldom been considered as dimensions of initial commitments that could influence persistence processes and outcomes. This study used NPSAS-87 to examine the influence of finance-related reasons for choosing a college on persistence decisions. The findings include (1) finance-related choices have direct and indirect influences on whether students persist in college; and (2) market-based, monetary measures of financial aid, tuition costs, housing costs, and other living costs have a substantial direct effect on persistence.     

Comparing Union and Nonunion Staff Perceptions of the Higher Education Work Environment

Evidence of substantial growth in unionization among university noninstructional staff over the past 20 years (Hurd and Woodhead, 1987) and the emergence of a quality movement in higher education linking employee attitudes toward the work environment with increased productivity point to the need for additional research into union and nonunion staff perceptions of the work environment. This paper describes a conceptually oriented, exploratory study of the university work environment as perceived and defined by union and nonunion noninstructional staff.     

On tonal pattern perception in monkeys (Cebus apella)

The monkey’s capacity to extract tonal pattern from a sequence of tones was assessed in four subjects that had the benefit of substantial past experience in discriminating, matching, and remembering acoustic stimuli. In Experiment 1, the monkeys failed to transfer their well-established matching behavior to the matching of two structured sequences of tones that differed primarily in tonal pattern, indicating that for them tonal pattern was not a salient feature of the acoustic stimuli. Experiment 2 was an attempt to encourage tonal pattern perception by employing, within a discrimination paradigm, very simple tonal patterns and multiple exemplars of the positive and negative patterns; the transfer design, borrowed from Hulse and Cynx (1985), was a powerful one for revealing tonal pattern perception. Verifying earlier results from our laboratory, there was little in the monkeys’ transfer performance to indicate that they had extracted tonal pattern from the acoustic stimuli. Major discriminative control seemed to be vested in the first tone of each exemplar. This apparent cognitive limitation may be rather general among animals, perhaps reflecting an intimate connection between the capacity for tonal pattern perception and that for acoustically based language.     

Conservation without Conversation Revisited: a replication and elaboration of the Wheldall‐Poborca findings on the nonverbal assessment of conservation of liquid quantity 1

A series of experiments by Wheldall and Poborca (1980) have demonstrated that more young children can conserve liquid volume when tested using a novel, nonverbal paradigm than when tested by conventional verbal assessment procedures. The present experiment attempted to replicate their findings and simultaneously assess the effects of two modifications to their original procedure. The results showed that the two modifications to the Wheldall and Poborca procedure—(i) inviting subjects to transform the liquid quantities themselves, instead of merely observing the experimenter do so and (ii) using an extended elaborated form of response training—did not significantly increase the number of children able to conserve liquid volume. However, the original Wheldall and Poborca findings were replicated, showing that some children are likely to be falsely classified as non‐conservers if assessed using traditional verbal assessment methods.