Engaging Diversity And Marginalization Through Participatory Action Research: A Model For Independent School Reform

Authored by a university researcher, school practitioner, and high school student, this article examines how independent schools can utilize participatory action research (PAR) to bolster diversity and inclusion efforts. A case study approach was taken to showcase a two-year PAR project at a progressive independent school that sought to: (a) enrich institutional knowledge of student diversity, (b) capture the present-day schooling experiences of historically marginalized students in independent school settings, and (c) develop a dynamic action plan to ameliorate school issues that emerged through the PAR inquiry process. Committed to institutional research that informs school policy and practice, we argue that PAR provides a rigorous, student-centered, and democratic model for independent school reform

Basic statistical analyses of candidate nickel-hydrogen cells for the Space Station Freedom

Nickel-Hydrogen (Ni/H2) secondary batteries will be implemented as a power source for the Space Station Freedom as well as for other NASA missions. Consequently, characterization tests of Ni/H2 cells from Eagle-Picher, Whittaker-Yardney, and Hughes were completed at the NASA Lewis Research Center. Watt-hour efficiencies of each Ni/H2 cell were measured for regulated charge and discharge cycles as a function of temperature, charge rate, discharge rate, and state of charge. Temperatures ranged from -5 C to 30 C, charge rates ranged from C/10 to 1C, discharge rates ranged from C/10 to 2C, and states of charge ranged from 20 percent to 100 percent. Results from regression analyses and analyses of mean watt-hour efficiencies demonstrated that overall performance was best at temperatures between 10 C and 20 C while the discharge rate correlated most strongly with watt-hour efficiency. In general, the cell with back-to-back electrode arrangement, single stack, 26 percent KOH, and serrated zircar separator and the cell with a recirculating electrode arrangement, unit stack, 31 percent KOH, zircar separators performed best

Exit, Voice, and the Role of Corporate Directors: Evidence from Acquisition Performance

This study examines the characteristics of corporate boards for 82 companies that attempted 106 acquisitions during the 1980s. We find that poor performance is more likely to occur in firms that have recently experienced higher turnover of outside and lower turnover of inside directors. Companies with smaller boards, more reputable members, and larger equity holdings also outperform their counterparts. Our results do not suggest that more outside directors lead to improved performance but that outsiders often resign from the board instead of challenging managerial shirking. We conclude that choosing directors for whom board exit is costly will better reduce agency costs.

Introduction to Probability with R

Abstracts not available for BookReview

The Impact of Recent Welfare Reforms on Labor Supply Behavior in New Zealand

New Zealand recently initiated sweeping reforms to its social welfare program by cutting benefits and tightening eligibility criteria. One of the objectives of these reforms was to provide incentives for people to enter or re-enter the labor force. Econometric analysis is used in this paper to isolate the actual effects of these benefit reforms on labor supply. Previous research has often failed to accurately measure the extent of these work disincentives, or to observe variation in these programs that would allow this empirical analysis to take place. The structure of the benefit programs and the nature of the reforms in New Zealand offer a unique opportunity to identify these behavioral responses. Quarterly random samples of individuals over the period 1987–1995 are used to isolate the effects of the reforms. This study finds compelling evidence that the recent benefit reforms in New Zealand increased both labor force participation and hours of labor supplied at the aggregate level.

Sub-Optimal Allocation of Time in Sequential Movements

The allocation of limited resources such as time or energy is a core problem that organisms face when planning complex actions. Most previous research concerning planning of movement has focused on the planning of single, isolated movements. Here we investigated the allocation of time in a pointing task where human subjects attempted to touch two targets in a specified order to earn monetary rewards. Subjects were required to complete both movements within a limited time but could freely allocate the available time between the movements. The time constraint presents an allocation problem to the subjects: the more time spent on one movement, the less time is available for the other. In different conditions we assigned different rewards to the two tokens. How the subject allocated time between movements affected their expected gain on each trial. We also varied the angle between the first and second movements and the length of the second movement. Based on our results, we developed and tested a model of speed-accuracy tradeoff for sequential movements. Using this model we could predict the time allocation that would maximize the expected gain of each subject in each experimental condition. We compared human performance with predicted optimal performance. We found that all subjects allocated time sub-optimally, spending more time than they should on the first movement even when the reward of the second target was five times larger than the first. We conclude that the movement planning system fails to maximize expected reward in planning sequences of as few as two movements and discuss possible interpretations drawn from economic theory

Planning Routes Across Economic Terrains: Maximizing Utility, Following Heuristics

We designed an economic task to investigate human planning of routes in landscapes where travel in different kinds of terrain incurs different costs. Participants moved their finger across a touch screen from a starting point to a destination. The screen was divided into distinct kinds of terrain and travel within each kind of terrain imposed a cost proportional to distance traveled. We varied costs and spatial configurations of terrains and participants received fixed bonuses minus the total cost of the routes they chose. We first compared performance to a model maximizing gain. All but one of 12 participants failed to adopt least-cost routes and their failure to do so reduced their winnings by about 30% (median value). We tested in detail whether participants’ choices of routes satisfied three necessary conditions (heuristics) for a route to maximize gain. We report failures of one heuristic for 7 out of 12 participants. Last of all, we modeled human performance with the assumption that participants assign subjective utilities to costs and maximize utility. For 7 out 12 participants, the fitted utility function was an accelerating power function of actual cost and for the remaining 5, a decelerating power function. We discuss connections between utility aggregation in route planning and decision under risk. Our task could be adapted to investigate human strategy and optimality of route planning in full-scale landscapes

MLDS: Maximum Likelihood Difference Scaling in R

The MLDS package in the R programming language can be used to estimate perceptual scales based on the results of psychophysical experiments using the method of difference scaling. In a difference scaling experiment, observers compare two supra-threshold differences (a,b) and (c,d) on each trial. The approach is based on a stochastic model of how the observer decides which perceptual difference (or interval) (a,b) or (c,d) is greater, and the parameters of the model are estimated using a maximum likelihood criterion. We also propose a method to test the model by evaluating the self-consistency of the estimated scale. The package includes an example in which an observer judges the differences in correlation between scatterplots. The example may be readily adapted to estimate perceptual scales for arbitrary physical continua