Simulation of complex survival distributions

This paper describes a method for generating sample survival distributions from a hypothetical population, as would be required for running Monte Carlo simulations. The method is based on the concept of a quincunx. Cases are entered into a life table and allowed to drop out or die during each interval with probabilities that mirror the hypothetical population. By repeating this process many times and tracking the results, the researcher is able to study the sampling distribution of effect size indices and test statistics, and can generate empirical estimates of power and precision for planned studies. Unlike other methods that are commonly used for this purpose, the model proposed here allows the researcher to define a population in which the hazard rates and/or attrition rates vary substantially from one time point to the next, as may be the case in clinical trials or studies of processing times. The method requires less than 100 lines of code and runs some 10,000 simulations per hour on a microcomputer.     

Characteristics of the Florida cognitive activities scale in older African Americans

Substantial research effort has recently focused on the potential protective effect of cognitively demanding activities on cognitive decline in late life. A significant methodological issue in this effort has been the lack of consistency in approaches to the operational measurement of cognitive activity. In this study, data in support of the reliability and construct validity of the recently developed Florida Cognitive Activities Scale (FCAS) in a sample of 223 African American older adults are provided. Consistent with the findings of the Schinka et al. study using a sample of Whites, the FCAS full scale showed a reasonably high level of internal consistency, small negative correlations with age and a measure of depressive symptomatology, and moderate positive correlations with years of education and neuropsychological measures of overall cognitive functioning, memory, and executive functioning. Even after controlling for the effects of age, education, and gender, the full scale score contributed significantly to the prediction of global cognitive functioning. The results of this study suggest that the FCAS is a reliable and valid measure of cognitive activities in older African Americans and provides additional, although not causative, evidence in support of the hypothesis of a protective effect of cognitive activity against cognitive decline regardless of ethnicity or race.     

The Wisdom of Caution: Genetic Enhancement and Future Children

Many scholars predict that the technology to modify unborn children genetically is on the horizon. According to supporters of genetic enhancement, allowing parents to select a child’s traits will enable him/her to experience a better life. Following their logic, the technology will not only increase our knowledge base and generate cures for genetic illness, but it may enable us to increase the intelligence, strength, and longevity of future generations as well. Yet it must be examined whether supporters of genetic enhancement, especially libertarians, adequately appreciate the ethical hazards emerging from the technology, including whether its use might violate the harm principle.     

Permanence and change in memory II. Reproduction of words in sentences

Abstract.— A retroactive interference paradigm was employed for studying qualitative memory changes. Sentences, containing an ambiguous word that was defined differently by succeeding words, were used as stimulus material. Such retroactive definitions of meaning were found to lead to qualitative changes in reproduction. It is suggested that the issue of permanence and change in memory may be related to the choice of lists of independent items or contextual units as stimulus material. A contextual theory of memory, implying the conception of memory in a stream, is advocated.     

The Boeing 737 MAX: Lessons for Engineering Ethics

Science and Engineering Ethics - The crash of two 737 MAX passenger aircraft in late 2018 and early 2019, and subsequent grounding of the entire fleet of 737 MAX jets, turned a global spotlight on...     

How Discrimination Impacts Sociopolitical Behavior: A Multidimensional Perspective

The conventional wisdom regarding the impact of discrimination on political behavior is that the perception of prejudiced treatment motivates individuals to take political action. This study challenges this common conception by demonstrating that the source of discrimination can play a significant role in whether perceived or experienced injustice leads to activism or withdrawal from sociopolitical life. Drawing from political science and social psychology literature, this study provides a new perspective on the potential effects of discrimination on a relatively new marginalized group in the United States. Specifically, an important distinction is drawn between political (systematic) and societal (interpersonal) discrimination in analyzing the sociopolitical behavior of American Muslims in the aftermath of the 9/11 terrorist attacks. The results will hopefully encourage scholars to take a deeper look at the nexus between discrimination and democratic engagement, which is an important, complex, multidimensional, and understudied topic.     

The Engineering and Science Issues Test (ESIT): A Discipline-Specific Approach to Assessing Moral Judgment

To assess ethics pedagogy in science and engineering, we developed a new tool called the Engineering and Science Issues Test (ESIT). ESIT measures moral judgment in a manner similar to the Defining Issues Test, second edition, but is built around technical dilemmas in science and engineering. We used a quasi-experimental approach with pre- and post-tests, and we compared the results to those of a control group with no overt ethics instruction. Our findings are that several (but not all) stand-alone classes showed a significant improvement compared to the control group when the metric includes multiple stages of moral development. We also found that the written test had a higher response rate and sensitivity to pedagogy than the electronic version. We do not find significant differences on pre-test scores with respect to age, education level, gender or political leanings, but we do on whether subjects were native English speakers. We did not find significant differences on pre-test scores based on whether subjects had previous ethics instruction; this could suggest a lack of a long-term effect from the instruction.     

A visual approach to statistical power analysis on the microcomputer

Computer programs for statistical power analysis typically require the user to provide a series of values and respond by reporting the corresponding power. These programs provide essentially the same functions as a published text, albeit in a more convenient form. In this paper, we describe a program that instead uses innovative graphic techniques to provide insight into the interaction among the factors that determine power. For example, fort tests, the means and standard deviations of the two distributions, sample sizes, and alpha are displayed as bar graphs. As the researcher modifies these values, the corresponding values of beta (also displayed as a bar graph) and power are updated and displayed immediately. By displaying all of the factors that are instrumental in determining power, the program ensures that each will be addressed By allowing the user to determine the impact that any modifications will have on power, the program encourages an appropriate balance between alpha and beta while working within the constraints imposed by a limited sample size. The program also allows the user to generate tables and graphs to document the impact of the various factors on power. In addition, the program enables the user to run on-screen Monte Carlo simulations to demonstrate the importance of adequate statistical power, and as such, it can serve as a unique educational tool.     

Statistical power analysis for one-way analysis of variance: A computer program

To facilitate the computation of statistical power for analysis of variance, Cohen developed the index of effect sizef, defined as theSD between groups divided by theSD within groups. A microcomputer program for statistical power allows the user to compute the value off in any of several ways: by specifying the mean andSD for every cell in the ANOVA; by specifying the mean value for the two extreme cells and the pattern of dispersion for the remaining cells; by estimating the proportion of variance in the dependent variable that will be explained by group membership; and/or with reference to conventions for small, medium, and large effects. The program will compute power for any single set of parameters; it will also allow the user to generate tables and graphs showing how power will vary as a function of effect size, sample size, andα.     

The Intervention of Robot Caregivers and the Cultivation of Children’s Capability to Play

In this article, the authors examine whether and how robot caregivers can contribute to the welfare of children with various cognitive and physical impairments by expanding recreational opportunities for these children. The capabilities approach is used as a basis for informing the relevant discussion. Though important in its own right, having the opportunity to play is essential to the development of other capabilities central to human flourishing. Drawing from empirical studies, the authors show that the use of various types of robots has already helped some children with impairments. Recognizing the potential ethical pitfalls of robot caregiver intervention, however, the authors examine these concerns and conclude that an appropriately designed robot caregiver has the potential to contribute positively to the development of the capability to play while also enhancing the ability of human caregivers to understand and interact with care recipients.