Relative costs and statistical power in the extreme groups approach

The relationship between variables in applied and experimental research is often investigated by the use of extreme (i.e., upper and lower) groups. Recent analytical work has provided an extreme groups procedure that is more powerful than the standard correlational approach for all values of the correlation and extreme group size. The present article provides procedures to optimize power by determining the relative number of subjects to use in each of two stages of data collection given a fixed testing budget.The opinions or assertions contained herein are those of the writers and are not to be construed as official or reflecting the views of the Navy Department.Edward F. Alf, Jr. is also affiliated with the Department of Psychology, San Diego State University.     

Parameter estimation in latent trait models

Latent trait models for binary responses to a set of test items are considered from the point of view of estimating latent trait parameters=( ₁, , _n ) and item parameters=( ₁, , _k ), where _j may be vector valued. With considered a random sample from a prior distribution with parameter, the estimation of (, ) is studied under the theory of the EM algorithm. An example and computational details are presented for the Rasch model.This work was supported by Contract No. N00014-81-K-0265, Modification No. P00002, from Personnel and Training Research Programs, Psychological Sciences Division, Office of Naval Research. The authors wish to thank an anonymous reviewer for several valuable suggestions.     

A more powerful method for testing for agreement between a judge and a known standard

We assume that a judge's task is to categorize each ofN subjects into one ofr known classes. The design of primary interest is employed if the judge is presented withs groups, each containingr subjects, such that each group of sizer consists of exactly one subject of each of ther types. The probability distribution for the total number of correct choices is developed and used to test the null hypothesis that the judge is guessing in favor of the alternative that he or she is operating at a better than chance level. The power of the procedure is shown to be superior to two other procedures which appear in the literature.The authors are grateful for the suggestions of the referees and for computer funding provided by the Northeast Regional Data Center at the University of Florida.     

Temporal control of behavior and the power law

The performance of rats and pigeons under fixed-interval schedules was studied in two experiments. The duration of postreinforcement pause was a declining proportion of fixed-interval duration. For pigeons this was true both when the duration of the reinforcer was fixed and when it was increased in direct proportion to increases in fixed-interval duration; the longer reinforcer durations did, however, lengthen the postreinforcement pause at higher schedule values. A quantitative analysis of data from Experiments 1 and 2 and from other studies showed that fractional exponent power functions described the relationship between postreinforcement pause and fixed-interval value; similar functions have previously been observed in studies of temporal differentiation. It was concluded that power functions reflect a direct causal, rather than artifactual, relationship between performance and the temporal requirements of reinforcement schedules.     

Concurrent schedules: a quantitative relation between changeover behavior and its consequences

Data from several published experiments on concurrent variable-interval schedules were analyzed with respect to the effects of changeover delay on the time spent responding on a schedule before changing to an alternate schedule: i.e., the interchangeover time. Interchangeover time increases as the duration of the changeover delay increases, and the present analysis shows that a power function describes the relation. The power relation applied in spite of numerous differences in the experiments: different variable-interval schedules for the concurrent pairs; equal or unequal reinforcement rates for the schedules of the concurrent pairs; different durations of the changeover delay; response-dependent or response-independent reinforcers; pigeons or rats as subjects; different reinforcers. A power function also described the data in experiments where the changeover incurred a timeout, where a fixed ratio was required to changeover, and also when asymmetrical changeover delays were used.     

“Liturgy emerges from a wound”

Serious academic reflection and scholarship on the Fresh Expressions of Church (FXoC) movement in the United Kingdom is developing significantly, but there exists almost no such work in South Africa. What has been produced deals with scholars reflecting on their experiences of Fresh Expressions in the United Kingdom (Ian Nell and Rudolph Grobler, “An Exploration of Fresh Expressions as Missional Church: Some Practical-Theological Perspectives,” NGTT DEEL 55:3–4 (2017), 747–68). This is an unfortunate situation. While there has been a generous response by many churches, there has been little interest, by and large, from the Anglican Church of Southern Africa (ACSA). FXoC is, then, an under-researched entity in South Africa. This article, part of a larger study, seeks to ask questions about how liturgy might develop from below in a new ecclesial community of marginalized people.     

权力感对道德判断的影响及其理论解释:基于CNI模型的视角

权力感指个体对控制他人和自身的能力的感知。现有权力对道德判断的影响研究主要使用传统两难困境范式,围绕权力感影响主体道德判断的功利论倾向与道义论倾向展开,且研究观点尚未达成共识。由于传统两难困境范式的局限性,研究者开发了道德判断CNI模型探究权力感对道德判断的影响,该模型为两者之间的关系提供了新的解释路径。未来研究可关注CNI模型视角下不同类型权力感对道德判断的影响以及探讨特质性权力感与情境性权力感对个体道德判断差异的联合作用。     

Selfish power and unselfish status in Chinese work situations

The present research explored the selfishness of power and status as well as the mechanism in Chinese work situations. By using experimental and survey methods, two studies were designed to investigate the relationships among power, status, and self‐interested behaviour (SIB) as well as the mediating effect of perspective‐taking (PT). Results of the two studies consistently indicated that power increases whereas status reduces SIB. These opposing behavioural effects are partially attributed to the fact that power reduces whereas status increases PT. In addition, our results showed an interaction between power and status on SIB in Study 1 (interaction as a mental function), and a positive correlation between perceived power and status in Study 2 (correlation as a mental perception). Through the discussion from the perspective of the self/other‐orientation trait, as well as the stable effects of power and status on SIB in the two studies, we conclude that power is selfish and status is unselfish in Chinese work situations.     

Mechanisms of Empowerment: Psychological Processes for Members of Power-based Community Organizations

The paper reports a study of participatory experiences among members of power-based community organizations. A path model of psychological empowerment was tested. Perceived relational characteristics of the community organization were hypothesized as exogenous to participation, perceived organizational power and psychological empowerment. An alternative model was reproduced with the strongest relationships between perceived organizational intimacy and psychological empowerment and an inverse relationship between perceived organizational regulation and perceptions of organizational power.     

Testing two variances for superiority/non-inferiority and equivalence: Using the exhaustion algorithm for sample size allocation with cost

The equality of two group variances is frequently tested in experiments. However, criticisms of null hypothesis statistical testing on means have recently arisen and there is interest in other types of statistical tests of hypotheses, such as superiority/non-inferiority and equivalence. Although these tests have become more common in psychology and social sciences, the corresponding sample size estimation for these tests is rarely discussed, especially when the sampling unit costs are unequal or group sizes are unequal for two groups. Thus, for finding optimal sample size, the present study derived an initial allocation by approximating the percentiles of an F distribution with the percentiles of the standard normal distribution and used the exhaustion algorithm to select the best combination of group sizes, thereby ensuring the resulting power reaches the designated level and is maximal with a minimal total cost. In this manner, optimization of sample size planning is achieved. The proposed sample size determination has a wide range of applications and is efficient in terms of Type I errors and statistical power in simulations. Finally, an illustrative example from a report by the Health Survey for England, 1995–1997, is presented using hypertension data. For ease of application, four R Shiny apps are provided and benchmarks for setting equivalence margins are suggested.