A maximum likelihood hierarchical disaggregate model for predicting choices of individuals

The absence of operational disaggregate lexicographic decision models and Tversky's observation that choice behavior is often inconsistent, hierarchical, and context dependent motivate the development of a maximum likelihood hierarchical (MLH) choice model. This new disaggregate choice model requires few assumptions and accommodates the three aspects of choice behavior noted by A. Tversky (1972, Journal of Mathematical Psychology, 9, 341–367). The model has its foundation in a prototype model developed by the authors. Unlike the deterministic prototype, however, MLH is a probabilistic model which generates maximum likelihood estimators of the aggregate “cutoff values.” The model is formulated as a concave programming problem whose solutions are therefore globally optimal. Finally, the model is applied to data from three separate studies where it is demonstrated to have superior performance over the prototype model in its predictive performance.     

What place does religion have in the ethical thinking of scientists and engineers?

Religion, defined as ‘the idea of a state that transcends ourselves and our world and the working out of the consequences of that idea’, may influence the ethical thinking of scientists and engineers in two ways. The first is at the level of the individual and how personal beliefs affect the choice of research, design or development projects, relationships with other researchers and the understandings of the consequences of research on other aspects of life. The second level is that of the social and cultural setting in which scientists and engineers work; how society decides which research to sponsor, how to apply the results of scientific discovery and which technology it chooses to develop and for what purposes. In neither of these areas is religious belief a necessary condition for scientists and engineers to pursue one course of action rather than another. The existence of religious belief within the individual and society is, though, part of the ethical framework in which scientist and engineers work and therefore something to which attention should be paid. Religion provides a particular perspective on what should be. Conversely science and technology provide information on the nature of the person and the universe in which we live, which must be taken into account when theologians and religious moralists apply their ethical norms and principles.     

Peripheral information extraction: A developmental examination of reading processes

Three experiments examining the information extraction processes are presented. In Experiments I and II, adults and children were presented paragraphs to read and search for specified targets, respectively. Two types of typographical (spatial) manipulations were used: case of the letters within the paragraphs was as normally experienced, or in alternating upper and lower case letters. Spacing between words was either as normal, filled with a neutral symbol, or absent. The response measures were reading and search speed in words per minute. Sensitivity to case (word shape) and space (word boundary) increased as a function of experience and was different for reading compared with search. In Experiment III subjects were asked to judge whether briefly presented pairs of letters were the same or different. Retinal (spatial) location was varied from trial to trial; dependent measure was reaction time. Results showed a developmental progression in response time with complex interactions. Theoretical interpretations of these data are discussed in support of the initial stage of Hochberg's peripheral to cognitive search guidance model.     

Topics and cases for online education in engineering

When considering offering online education for engineering ethics instruction, making choices necessary for the effective development and delivery of an engineering ethics curriculum is an important first step. Selecting the topics and types of cases for the most effective ethics education of engineering students is a vital step in preparing an effective program. Examples are presented for topics which are considered good candidates for online presentation, and the adaptability of these topics for web-based instruction is discussed. Types of cases which are useful in engineering ethics education are presented. Methods of teaching applied ethics, as well as ideas for web-based ethics course design are suggested. The market for web-based instruction is discussed.     

The role of functionality in the mental representations of engineering students: some differences in the early stages of expertise

As engineers gain experience and become experts in their domain, the structure and content of their knowledge changes. Two studies are presented that examine differences in knowledge representation among freshman and senior engineering students. The first study examines recall of mechanical devices and chunking of components, and the second examines whether seniors represent devices in a more abstract functional manner than do freshmen. The most prominent differences between these 2 groups involve their representation of the functioning of groups of electromechanical components and how these groups of components interact to produce device behavior. Seniors are better able to construct coherent representations of devices by focusing on the function of sets of components in the device. The findings from these studies highlight some ways in which the structure and content of mental representations of design knowledge differ during the early stages of expertise acquisition.     

Comparison of women engineers who persist in or depart from engineering

The current research examined differences between women engineers who persisted in an engineering career versus those who left engineering using a combination of two prominent theories of career change: social cognitive career theory (SCCT, Lent, Brown & Hackett, 1994; 2002) and integrated model of career change (Rhodes & Doering, 1983). The two groups of women did not differ in three domains of self-confidence or outcome expectations (engineering tasks, navigating organizational climate, or multiple roles), in vocational interests, or in workplace barriers. Women who continue in engineering do differ from those who leave in their experience of workplace supports and their levels of occupational commitment. Engineering turnover intentions and occupational commitment emerged as the two key variables that explained 33.4% of the variance in persistence in engineering careers. We discuss the implications of the results in terms of theoretical development and practical implications for organizations.     

Engineering with Uncertainty: Monitoring Air Bag Performance

Modern engineering is complicated by an enormous number of uncertainties. Engineers know a great deal about the material world and how it works. But due to the inherent limits of testing and the complexities of the world outside the lab, engineers will never be able to fully predict how their creations will behave. One way the uncertainties of engineering can be dealt with is by actively monitoring technologies once they have left the development and production stage. This article uses an episode in the history of automobile air bags as an example of engineers who had the foresight and initiative to carefully track the technology on the road to discover problems as early as possible. Not only can monitoring help engineers identify problems that surface in the field, it can also assist them in their efforts to mobilize resources to resolve problem.     

Comments on ‘On “Bettering Humanity” in Science and Engineering Education’

The object of this communication is to reflect on the recent article by James Stieb in relation to an earlier article by Selvan.     

The epistemic implications of engineering rhetoric

The texts (and talk) of engineers take different forms. In this essay, I present and critique several texts written for different purposes and audiences but all intended to convey to the reader the technical details of whatever they are about—whether a textbook passage describing the fundamental behavior of an electrical component, a journal article about a mathematical technique intended for use in design optimization, a memo to co-workers within a firm about a heat transfer analysis of a remotely sited building, or a general introduction to the field of? ergonomics? My aim is to explore how the ways in which engineers describe and document their problems and projects frame what they accept, display and profess as useful knowledge. In this I am particularly interested in how engineers envision the ‘users’ of, or participants in, their productions. Like science, engineering texts are written as if they were timeless and untainted by socio-cultural features. However, a technical treatise is not devoid of metaphor or creative rendering of events; there is always a narrative within which worldly data and instrumental logic is embedded—but it is a story in which the passive voice prevails, history is irrelevant, and the human actor or agent is painted in quantitative parameters fitting the occasion. Whether this rhetoric can be sustained in the face of challenges to traditional ways of doing engineering is an open question.