The Vanishing 2×2 Table: Linking the Hypergeometric,Binomial and Poisson

A simple procedure for establishing minimum sample size in X ² goodness-of-fit tests is presented. Samples of this size will automatically satisfy Yarnold's criterion.     

Estimating improvement in prediction with matched case–control designs

When an existing risk prediction model is not sufficiently predictive, additional variables are sought for inclusion in the model. This paper addresses study designs to evaluate the improvement in prediction performance that is gained by adding a new predictor to a risk prediction model. We consider studies that measure the new predictor in a case–control subset of the study cohort, a practice that is common in biomarker research. We ask if matching controls to cases in regards to baseline predictors improves efficiency. A variety of measures of prediction performance are studied. We find through simulation studies that matching improves the efficiency with which most measures are estimated, but can reduce efficiency for some. Efficiency gains are less when more controls per case are included in the study. A method that models the distribution of the new predictor in controls appears to improve estimation efficiency considerably.     

How leadership matters: The effects of leaders' alignment on strategy implementation

Research has confirmed that leader behavior influences group and organizational behavior, but we know less about how senior leaders ensure that group and organizational members implement their decisions. Most organizations have multiple layers of leaders, implying that any single leader does not lead in isolation. We focused on how the consistency of leadership effectiveness across hierarchical levels influenced the implementation of a strategic initiative in a large health care system. We found that it was only when leaders' effectiveness at different levels was considered in the aggregate that significant performance improvement occurred. We discuss the implications of these findings for leadership research, specifically, that leaders at various levels should be considered collectively to understand how leadership influences employee performance.     

Delivering Health Care to Aborigines

The people have the right and duty to participate individually and collectively in the planning and implementation of their health care.¹     

Impact of Bereavement on the Self-Conceptions of Older Surviving Spouses

The purpose of this longitudinal study was to assess the extent to which the social anchorage dimension of the self-concept is impacted by the death of a spouse among a sample of older surviving spouses. Social anchorage was measured by the Twenty Statements Test (TST) in mailed questionnaires and consisted of self-statements that signify important social relationships and group memberships. As hypothesized, the 42 bereaved persons had lower social anchorage scores than the 72 nonbereaved controls. This significant effect was evident as early as three to four weeks following the death, and it persisted through five more measurement periods that covered the first two years of bereavement.     

White,black, and Hispanic male youths in central city labor markets

Data from the 1% 1980 Census Public Use Sample are used to estimate the determinants of employment and wage rates for out-of-school male youths residing in central cities. Separate calculations are undertaken for white, black, and Hispanic youths. Independent variables include individual, family background, and local labor market characteristics. Three basic findings emerge. First, racial inequality persists, with whites showing the best outcomes, Hispanics second, and blacks at the bottom. Second, underlying these unequal outcomes are rather different patterns of effect for personal and family characteristics by race. Note-worthy here is the Hispanic pattern of low reliance on schooling and high reliance on family. Finally, net of these effects, intercity differences are interesting and important. These include negative effects of city size and race composition effects which show white gains where blacks and Hispanics are a larger share of the population.     

USING REPEATED MEASURES DESIGNS IN PROGRAM EVALUATION OF FAMILY THERAPY*

Data from 14 simulated families were analyzed with both a repeated measures and an ordinary analysis of variance design in order to illustrate the differences between the two approaches. The advantages of repeated measures designs for the analysis of family data in the program evaluation of family therapy are highlighted.