A Six-Year Longitudinal Study of Undergraduate Women in Engineering and Science*

In 1991, the Women in Engineering (WIE) Initiative at the University of Washington was funded by the Alfred P. Sloan Foundation to conduct a longitudinal study of undergraduate women pursuing degrees in science or engineering. Cohorts of approximately 100 students have been added to the study each year, for a current total of 672 participants. The objectives are: (a) to determine an accurate measure of retention by tracking individual students through their science and engineering academic careers; (b) to examine factors affecting retention of women in science and engineering; and (c) to evaluate the effectiveness of WIE's programs targeted at increasing enrollment and retention of women in science and engineering. These programs include interventions primarily during the freshman and sophomore years, which are critical attrition points. The results of this study are reported annually to the Dean of Engineering and related departments for consideration in policy formulation. Annual results of the study have shown consistent patterns of persistence factors and barriers for these high-achieving women; most notably a significant drop in academic self-confidence during their freshman year in college. In addition, individual tracking of these women has shown a retention that is much higher than the estimated national average for engineering and science students.     

Selecting a Model for Freshman Engineering Design

This paper describes a process undertaken at the University of Alaska Fairbanks to select a model for teaching freshman engineering design. The project identified and characterized methods in use for teaching freshman design, and selected method(s) appropriate for UAF with general recommendations for implementation. Background research included a needs and information survey of freshmen and senior engineers, and research on methods currently used to teach design at ABET accredited colleges and universities. Eight methods for teaching design to freshman engineering students were identified. A Weighted Factor Scoring Model was used to determine which methods of teaching design were most applicable to UAF. A reverse engineering model was selected and proposed for the new freshman engineering design course. The methodology, results, and other considerations are discussed.     

Fundamentals Of Engineering Energy

Three new Fundamentals of Engineering courses, entitled Energy, Materials and Systems are presented in the sophomore year of the Drexel University E⁴ program. The first focuses on the concept, manifestations, uses, conservation, storage, transformation, and transfer of energy. The second focuses on materials to establish, interpret and utilize the relationships that exist between processing/synthesis, microstructure, properties, and performance-for metals, ceramics, polymers and composites. The third focuses on systems, capitalizing on the up-front-engineering theme of the E⁴ curriculum and the extensive use of computer methods to equip students with concepts and methods of analysis which are common to all branches of engineering. All courses integrate mathematics, science, and engineering as a central theme. The subject matter builds upon the freshman courses to prepare a common strong foundation in the fundamentals of engineering for all students regardless of major. Faculty from science and engineering collaborate in preparing and presenting these courses. This interdisciplinary communication, frequently lacking in the traditional program, is an important feature of the E⁴ program. Student performance in these and upper-division courses indicates that the educational objectives are being achieved. Surveys of student opinions show a high degree of interest in the subject matter and satisfaction with the methodologies adopted.     

Characteristics of Freshman Engineering Students: Models for Determining Student Attrition in Engineering

Nationwide, less than half the freshman who start in engineering graduate in engineering, and at least half of this attrition occurs during the freshman year. Clearly, the freshman year is critical for both academic success and retention of engineering students. Such success depends not only on the knowledge and skills learned during this first year, but also on the attitudes individual students bring with them to college. Hence, if these attitudes can be measured before beginning college, we can develop more targeted programs for reducing attrition and improving academic success. Further, by measuring changes in student attitude over the course of the freshman year, we can develop better methods to evaluate engineering education programs. To learn more about these attitudes and how they impact upon retention, we undertook a three-year research effort. First we identified attitudes incoming students have about the field of engineering, their perceptions about the upcoming educational experience, and their confidence in their ability to succeed in engineering. These attitudes were then related to performance and retention in the freshman engineering program. To accomplish this, a closedform survey was developed, tested and administered to the 1993–94 and 1994–95 freshman engineering classes. This study demonstrated that student attitudes can provide an effective means for evaluating aspects of our freshman engineering program, particularly those relating to issues of attrition. Specifically, students who left the freshman engineering program in “good academic standing” had significantly different attitudes about engineering and themselves than those possessed by other comparison groups: students who stayed in engineering and students who left engineering in “poor academic standing.” We developed regression models to predict attrition and performance in our freshman engineering program using quantified measures of student attitudes. Implementation of the models has allowed freshman advisors to better inform students of opportunities that engineering offers, to devise better programs of study that take advantage of students' varied interests, and to set retention goals that are more realistic.     

Comparing the Undergraduate Experience of Engineers to All Other Majors: Significant Differences are Programmatic

Background The authors partnered with the National Survey of Student Engagement (NSSE) to examine how persistence within the engineering major and engagement of undergraduate students in engineering compare to other majors. Purpose (Hypothesis ) We explored three research questions: How do engineering students rate their college engagement compared to students in other majors? How do engineering persisters, non‐persisters, and migrators compare in terms of collegiate engagement, time on task, and enriching educational experiences? What college engagement factors predict persistence in engineering? Design /Method Data are from nearly 12,000 students who completed the NSSE survey in their first and senior years as undergraduates. Surveys were analyzed using ANOVA and Chi‐square calculations to determine whether differences emerged in three dimensions of student engagement based on students' self‐reported major. Due to the large sample, effect size was used to determine statistical significance. Binary logistic regression was used to identify factors that predict persistence among first year students and seniors in engineering. Results Results show that engineering majors are similar to non‐engineering majors on most variables. However, engineering majors reported significantly higher gains in practical competence and higher order thinking, but the lowest means on reflective learning and gains in general education. Engineering majors reported significantly more time preparing for class and less time participating in educationally enriching experiences. Conclusions We conclude that different educational outcomes between majors are the result of programmatic differences. The packed engineering curriculum requires students to make trade‐offs between gaining practical/marketable skills and participating in educationally enriching activities. We question this trade‐off and suggest alternative approaches.     

Is Modeling of Freshman Engineering Success Different from Modeling of Non‐Engineering Success?

The engineering community has recognized the need for a higher retention rate in freshman engineering. If we are to increase the freshman retention rate, we need to better understand the characteristics of academic success for engineering students. One approach is to compare academic performance of engineering students to that of non‐engineering students. This study explores the differences in predicting academic success (defined as the first year GPA) for freshman engineering students compared to three non‐engineering student sectors (Pre‐Med, STEM, and non‐STEM disciplines) within a university. Academic success is predicted with pre‐college variables from the UCLA/CIRP survey using factor analysis and regression analysis. Except for the factor related to the high school GPA and rank, the predictors for each student sector were discipline specific. Predictors unique to the engineering sector included the factors related to quantitative skills (ACT Math and Science test scores and placement test scores) and confidence in quantitative skills.     

Integrating Design into the Sophomore and Junior Level Mechanics Courses

Engineering schools across the country are developing ways of integrating design into their curriculum, and a question that often arises is how to best integrate design into the sophomore and junior level courses. Freshman design projects or mechanical dissection courses are designed to give the students hands-on experience in conceptual design and construction, with little if any of the mathematical modeling normally used in engineering design. The capstone senior design project is a true engineering design experience, where students draw from their background to conceptualize, analyze, model, refine, and optimize a product to meet design, manufacturing, and life cycle cost requirements. The sophomore and junior level courses should assist students in making the transition from the “seat-of-the-pants” freshman design approach to the engineering design approach required for the capstone experience and engineering practice. This paper summarizes a three year effort at integrating design into the Mechanics of Materials course, but the principal conclusions drawn would apply to most sophomore and junior engineering science courses.     

Outcomes of a Longitudinal Administration of the Persistence in Engineering Survey

Background Understanding more about student decisions to leave engineering may lead to higher retention. This study builds on the literature and focuses on the experiences of a cohort of students who aimed to complete their undergraduate work in 2007. Purpose (Hypothesis ) This paper presents the outcomes of the longitudinal administration of the Persistence in Engineering survey. The goal was to identify correlates of persistence in undergraduate engineering education and professional engineering practice. Design /Method The survey was administered seven times over four years to a cohort of students who had expressed interest in studying engineering. At the end of the study, the participants were categorized as persisters or non‐persisters. Repeated measures analysis of variance was used, in conjunction with other approaches, to test for differences between the groups. Results Persisters and non‐persisters did not differ significantly according to the majority of the constructs. Nevertheless, parental and high school mentor influences as a motivation to study engineering, as well as confidence in math and science skills, were identified as correlates of persistence. Intention to complete an engineering major was also a correlate of persistence; it appears to decline sharply at least two semesters prior to students leaving engineering. The findings also suggest that there might be differences among non‐persisters when they are further grouped by when they leave engineering. Conclusions Facilitating higher levels of mentor involvement before college might increase student motivation to study engineering, and also constitute a mechanism for fostering confidence in math and science skills. Since the intention to complete an engineering degree decreases well before students act, there may be opportunities for institutions to develop targeted interventions for students, and help them make informed decisions.     

涉及离散变量的函数统计矩点估计法

点估计法对于仅包含连续随机变量的函数和系统的随机分析具有原理简洁清晰、操作简单易行的优点,并可以直接给出除均值和标准差之外的其他低阶统计矩。然而,对于客观存在的或者是需处理为的涉及离散随机变量的系统,现有的点估计法无能为力。为解决这一问题,该文基于一般随机系统的形式解析解,导出了涉及离散变量函数和系统的统计矩估计的理论表达式;然后,将其与现有的点估计法相结合,给出了涉及离散变量的函数和系统的低阶矩估计的点估计法;最后,通过理论推导和算例分析两种方式验证了建议方法的合理性和有效性,且指出该方法对包含离散变量的一般工程随机系统分析的适用性。     

The Engage Program: Implementing and Assessing a New First Year Experience at the University of Tennessee

The Engage initiative at the University of Tennessee addresses the needs of entering engineering students through a new first year curriculum. The program integrates the engineering subject matter of the freshman year, teaches problem solving and design by application, and seeks to address the increased retention and graduation of engineering students. Noteworthy curriculum features of the Engage program include a hands‐on laboratory where students do physical homework to practice the concepts introduced in lectures, placing all freshman engineering students in a year‐long team design curriculum, and a team training course where engineering upperclassmen are trained in team facilitation techniques and placed as facilitators with the freshman design teams. The Engage program was piloted during the 1997–98 academic year with 60 students. In 1998–99, the program was scaled up to 150 students, and fully implemented with the entire freshman class of 465 students during the 1999–2000 academic year. Engage students have shown a significant increase in academic performance compared to students following a more traditional curriculum. Graduation statistics show the positive long‐term results of this effort.     

可靠度对随机变量及失效模式相关系数的敏感度分析及其工程应用

客观存在的诸多不确定性因素使得工程不可避免地存在着风险。随着重大工程的不断涌现,人们越来越关心如何提高工程系统的安全度,降低工程结构的风险。遗憾的是如何降低工程系统的风险直至目前还没有固定的科学方法,大多是基于工程师的经验。以可靠度理论为基础,从可靠度对工程结构的某些参数的敏感性及可靠度对失效模式的相关系数入手,探讨如何从加强或削弱结构参数及失效模式间的相关性的角度出发,来进行降低结构风险的研究。给出了两个算例来说明方法在工程中的应用。     

Mathematical and Scientific Foundations for an Integrative Engineering Curriculum

All fields of engineering, whether chemical, civil, electrical, materials, mechanical, etc., encompass a common body of essential mathematics and science. In the freshman year of Drexels E⁴ program, this common mathematical and scientific foundation is cultivated in the Mathematical and Scientific Foundations of Engineering I, II and III (MSFE I, MSFE II, MSFE III). In an integrated fashion, MSFE I presents the essential calculus, physics and engineering mechanics vital to the freshman engineering student. In the first two quarters, MSFE II presents chemistry with clearly defined engineering applications and significance: in the third quarter, MSFE II presents living systems with the same thrust. Also in the third quarter, MSFE III presents basic circuits and circuit elements, and a brief introduction to electromagnetic theory.     

Empirical comparison of tree ensemble variable importance measures

Tree ensembles are becoming well-established as popular and powerful data modelling techniques. Tree ensemble models are essentially black box models, although their individual members may not be, and with their growing popularity, interest in the interpretation of tree ensemble models has also grown. This study presents variable importance measures associated with random forests, conditional inference forests and boosted trees, and employs a number of simulated data sets to compare these methods. Overall, variable importance indicators based on bagged conditional inference forests appear to strike a good balance between identification of significant variables and avoiding unnecessary flagging of correlated variables. Data preprocessing and interpretation by experts knowledgeable with a specific data set remain vital.     

An Examination of Indicators of Engineering Students' Success and Persistence

Student success and persistence within the major and university were examined through hierarchical linear and logistic regression analyses for two cohorts of engineering students. Indicators of success and persistence were based on theoretical and empirical evidence and included both cognitive and noncognitive variables. Cognitive variables included high school rank, SAT scores, and university cumulative grade point average. Noncognitive factors included academic motivation and institutional integration. Outcome variables included grade point average, enrollment at the university, and status as an engineering major. Gender differences also were evaluated. Several significant relationships among the variables were found. For instance, increased levels of motivation were significantly related to continuing in the major. Implications and directions for future research are discussed.     

Engineering Freshman Enrollments: Critical and Non-critical Factors

Freshman enrollment and bachelors degree data over the last three decades for all undergraduates as well as engineering students are analyzed and compared to variations in the numbers of high school graduates. Engineering enrollment data trends are shown to differ significantly from those of undergraduates as a whole and to exhibit little correlation with trends in high school graduation data. Freshman engineering enrollments show a very strong correlation with factors which might indicate to high school students the magnitude of their personal economic gain such as on-campus industrial interviewing intensity, annual growth in starting salaries and starting salary levels relative to average salaries of all undergraduates. No correlation between engineering freshman enrollments and national economic conditions as measured by the Gross Domestic Product or unemployment was found. Implications of the correlation between freshman enrollments and perceived personal economic reward are considered in terms of strategies for recruiting freshmen, student performance in engineering curricula and trends for the future.     

Time-varying reliability method based on linearized Nataf transform

In actual engineering, material properties, load effects, and other factors of mechanical structures change due to long-term use. In order to understand the operation of a mechanical structure in real time, it is crucial to obtain the dynamic trajectory of its reliability. Considering the time variability of a mechanical structure over time, uncertain random variables are introduced to express the uncertainty of various parameters of structures, and the Wiener process is used to describe the strength degradation process of structures so as to solve the calculation problem of time-varying reliability of mechanical structures. Based on the advanced first-order and second moment method (AFOSM), the proposed linearized Nataf change is used to complete the transformation from related nonnormal variables to independent standard normal variables in order to simplify the calculation process of reliability solution and solve the reliability calculation problem of random parameters subjected to arbitrary distribution. The deduced random variable sensitivity factor indicates the degree of influence of different random variables on the reliability of the mechanical structure, providing a theoretical basis for the optimal design and maintenance of a mechanical structure. The proposed method is analyzed using the cantilever beam and compared with the nonlinear Nataf transform and verified by the Monte Carlo simulation results. The results show that the proposed method can effectively solve the reliability sensitivity problem of structural system strength degradation.     

Reliability sensitivity analysis with random and interval variables

In reliability analysis and reliability‐based design, sensitivity analysis identifies the relationship between the change in reliability and the change in the characteristics of uncertain variables. Sensitivity analysis is also used to identify the most significant uncertain variables that have the highest contributions to reliability. Most of the current sensitivity analysis methods are applicable for only random variables. In many engineering applications, however, some of uncertain variables are intervals. In this work, a sensitivity analysis method is proposed for the mixture of random and interval variables. Six sensitivity indices are defined for the sensitivity of the average reliability and reliability bounds with respect to the averages and widths of intervals, as well as with respect to the distribution parameters of random variables. The equations of these sensitivity indices are derived based on the first‐order reliability method (FORM). The proposed reliability sensitivity analysis is a byproduct of FORM without any extra function calls after reliability is found. Once FORM is performed, the sensitivity information is obtained automatically. Two examples are used for demonstration. Copyright © 2009 John Wiley & Sons, Ltd.     

Development of Engineering Education as a Rigorous Discipline: A Study of the Publication Patterns of Four Coalitions

A combination of publication analysis and faculty interviews was employed to study four NSF‐sponsored engineering education coalitions as a case study of the recent history of engineering education. Current calls within the engineering education community for increased rigor can be understood in terms of the ways similar disciplines have emerged. In science education, for example, time was needed to develop consensus on important research questions, accepted methods, and standards of rigor. The abstracts of 700 publications listed on active engineering education coalition Web sites were analyzed over time by type of intervention, population of focus, and product. A picture consistent with other reports of coalition contributions emerged. Early focus was on freshman courses and integrating across disciplines, with teamwork, design and other active learning activities. Students and course improvement remained the dominant focus, but efforts increased over time in assessment, faculty development, and research. Interviews with coalition leaders and leading authors supplement the publication analysis and describe how coalition work helped lay the foundation for more rigorous engineering education research.     

Science Fiction in the Engineering Classroom to Help Teach Basic Concepts and Promote the Profession

Although science fiction has appeared in science and physics education for many years, the genre has not been widely used to augment engineering education. Considering the potential for science fiction to help illustrate many common engineering concepts, while at the same time challenging the students to think about the many possibilities of design and technology, this exclusion represents a loss of a valuable resource. In order to begin utilizing this valuable resource, a new freshman‐level course was developed that uses science fiction films and literature to illustrate and teach basic engineering concepts. Central to the course delivery is “poking fun” at the disobedience of the laws of nature and misuse of engineering while at the same time teaching the correct behaviors. By illustrating basic engineering concepts in this fashion, students can hopefully develop lasting mental pictures of the way things function and the complexities of design. These images can in turn, help the students with core mechanics classes such as statics and dynamics, as well as help the creative design process. Moreover, by highlighting the valuable role engineering plays in transferring science theory to usable technology, the discussions may also help create a positive image of the profession that could aid recruitment and retention. Finally, the genre can also be used to illustrate the implications of technology and society, along with the many ethical considerations of engineering.     

Persistence,Engagement, and Migration in Engineering Programs

Records from the Multiple‐Institution Database for Investigating Engineering Longitudinal Development indicate that engineering students are typical of students in other majors with respect to: persistence in major; persistence by gender and ethnicity; racial/ethnic distribution; and grade distribution. Data from the National Survey of Student Engagement show that this similarity extends to engagement outcomes including course challenge, faculty interaction, satisfaction with institution, and overall satisfaction. Engineering differs from other majors most notably by a dearth of female students and a low rate of migration into the major. Noting the similarity of students of engineering and other majors with respect to persistence and engagement, we propose that engagement is a precursor to persistence. We explore this hypothesis using data from the Academic Pathways Study of the Center for the Advancement of Engineering Education. Further exploration reveals that although persistence and engagement do not vary as much as expected by discipline, there is significant institutional variation, and we assert a need to address persistence and engagement at the institutional level and throughout higher education. Finally, our findings highlight the potential of making the study of engineering more attractive to qualified students. Our findings suggest that a two‐pronged approach holds the greatest potential for increasing the number of students graduating with engineering degrees: identify programming that retains the students who come to college committed to an engineering major, and develop programming and policies that allow other students to migrate in. There is already considerable discourse on persistence, so our findings suggest that more research focus is needed on the pathways into engineering, including pathways from other majors.