Thomas Aquinas on Virtuous Warfare

Thomas Aquinas, one of the founding fathers of just war theory, offers an account of virtuous warfare in practice. The author argues that Aquinas's approach to warfare, with its emphasis on justice and charity, is helpful in providing a coherent moral account of war to which Christians can subscribe. Particular attention is given to the role of charity, since this virtue is the distinguishing characteristic of the Christian soldier. Charity compels him to soldier justly, and by fighting justly, he is elevated by God to friendship with God. Notable features of this approach are its emphasis on the criteria for judging whether a war is just and its relativizing of the criteria for proper combat behavior.     

Writing programs on the Apple for the student psychology laboratory: Routines,subroutines, and sources of information

Writing programs for the student psychology laboratory on the Apple II series of microcomputers presents the programmer with a number of problems. Among these are increasing program execution speed, obtaining precise response and interval timing, reducing program memory requirements, obtaining efficient disk I/O, providing good error trapping, and presenting clear screen displays. Since Applesoft BASIC is not equipped with many of the desirable features of a more advanced language, ways to solve these problems are not obvious. This paper suggests a number of potential solutions and provides additional sources of information.     

A comparison of inexpensive statistical packages for apple II microcomputers

The purpose of this paper is to describe and compare some inexpensive software packages that calculate a variety of statistics on the Apple II microcomputer. For each package, hardware requirements, program capacity, limitations, constraints, accuracy, editing, error handling, and other features were studied.     

Writing high-quality statistical software for Apple II microcomputers

The purpose of this paper is to describe some principles and techniques that programmers should consider when trying to improve or create a statistical package. Four computational issues are discussed: accuracy, speed, computing probabilities, and error trapping. A single-array data structure is proposed for use within the program. Several other input-output issues are covered, including menus, command languages, questions, data input and editing, CRT and printer formatting, and graphics.     

Estimating item parameters and latent ability when responses are scored in two or more nominal categories

A multivariate logistic latent trait model for items scored in two or more nominal categories is proposed. Statistical methods based on the model provide 1) estimation of two item parameters for each response alternative of each multiple choice item and 2) recovery of information from wrong responses when estimating latent ability. An application to a large sample of data for twenty vocabulary items shows excellent fit of the model according to a chi-square criterion. Item and test information curves are compared for estimation of ability assuming multiple category and dichotomous scoring of these items. Multiple scoring proves substantially more precise for subjects of less than median ability, and about equally precise for subjects above the median.Preparation of this paper was supported in part by N.S.F. Grant GS-2900.     

Fitting a response model forn dichotomously scored items

A method of estimating the parameters of the normal ogive model for dichotomously scored item-responses by maximum likelihood is demonstrated. Although the procedure requires numerical integration in order to evaluate the likelihood equations, a computer implemented Newton-Raphson solution is shown to be straightforward in other respects. Empirical tests of the procedure show that the resulting estimates are very similar to those based on a conventional analysis of item difficulties and first factor loadings obtained from the matrix of tetrachoric correlation coefficients. Problems of testing the fit of the model, and of obtaining invariant parameters are discussed.Research reported in this paper was supported by NSF Grant 1025 to the University of Chicago.     

Marginal maximum likelihood estimation of item parameters: Application of an EM algorithm

Maximum likelihood estimation of item parameters in the marginal distribution, integrating over the distribution of ability, becomes practical when computing procedures based on an EM algorithm are used. By characterizing the ability distribution empirically, arbitrary assumptions about its form are avoided. The Em procedure is shown to apply to general item-response models lacking simple sufficient statistics for ability. This includes models with more than one latent dimension.Supported in part by NSF grant BNS 7912417 to the University of Chicago and by SSRC (UK) grant HR6132 to the University of Lancaster.We are indebted to Mark Reiser and Robert Gibbons for computer programming. David Thissen clarified a number of points in an earlier draft.     

Causal Attributions and Sex Differences Associated With Perceptions of Occupational Barriers

This study extends previous research addressing sex differences in perceived occupational barriers and evaluates the mediating role of causal attributions in the relationship between perceived occupational barriers and career maturity. Participants (85 women and 30 men) listed their perceived barriers to occupational goals, completed a measure of attributions for career decision making, and completed 2 different measures of career maturity. Findings revealed that a larger proportion of women than men perceived past barriers associated with family-related issues. Results also revealed a significant, negative relationship between the number of perceived occupational barriers and career maturity for participants who believe that career decision making is an externally caused, uncontrollable process. The implications of these findings and suggestions for career counselors to integrate perceived barriers into the counseling process are discussed.     

Ethnic Differences in College Students' Perceptions of Barriers to Career Development

Undergraduates (N = 375) representing various ethnic groups indicated perceived barriers to their past and future career development. Significant ethnic differences were revealed (p < .05).     

Recall norms of common spaces and activities of college students

To collect normative data on familiar spaces and behaviors of college students, two recall tasks were performed. In Experiment 1, 219 undergraduates recalled spaces where they spend time. In Experiment 2,155 undergraduates recalled the kinds of activities they do in familiar spaces. The norms provided here include 40 spaces and 123 different behaviors. Gender differences and transituational behaviors are also reported.