Estimating confidence intervals for eigenvalues in exploratory factor analysis

Exploratory factor analysis (EFA) has become a common procedure in educational and psychological research. In the course of performing an EFA, researchers often base the decision of how many factors to retain on the eigenvalues for the factors. However, many researchers do not realize that eigenvalues, like all sample statistics, are subject to sampling error, which means that confidence intervals (CIs) can be estimated for each eigenvalue. In the present article, we demonstrate two methods of estimating CIs for eigenvalues: one based on the mathematical properties of the central limit theorem, and the other based on bootstrapping. References to appropriate SAS and SPSS syntax are included. Supplemental materials for this article may be downloaded from http://brm.psychonomic-journals.org/content/supplemental.     

What Studies of Actors and Acting Can Tell Us About Memory and Cognitive Functioning

ABSTRACT— The art of acting has been defined as the ability to live truthfully under imaginary circumstances. Our many years of researching theatrical expertise have produced findings relevant to text comprehension, learning theory, cognitive aging, and expert memory. In this article, we first discuss how large amounts of dialogue, learned in a very short period, can be reproduced in real time with complete spontaneity. We then turn to abstracting the essence of acting and applying it to diverse undertakings, from discovering optimal learning strategies to promoting healthy cognitive aging. Finally, we address the implications of acting expertise on current theories of embodied cognition.     

The consistency and structure of aspect-based career preferences

Career aspects (e.g., work environment, using verbal ability, length of training, teamwork) are an elaboration and extension of vocational interests. Aspect-based preferences can serve individuals and their career counselors only if they are reliable and stable. Study 1 estimated the two-week test–retest reliability of 213 college freshmen's preferences in 31 career aspects and the two-year stability of these preferences for 132 of these freshmen. The two-week reliability and the two-year stability of both the within-aspect preferred levels (e.g., “only indoors” most preferred, but “mostly indoors” is also acceptable) and the aspect importance were tested for each of the aspects. The interquartile ranges of the two-week reliability of the aspect importance and of the preferred within-aspect levels were .54–.62 and .63–.74 for the 31 aspects; the interquartile ranges of the two-year stabilities were .38–.48 and .48–.59, respectively. These interquartile ranges reflect the variance in consistency among the aspects. Study 2 explored the structure of the aspects based on the pattern of associations among them. In addition, it examined the consistency of the aspect structures by comparing them in four samples (total N = 40,313). The structure was found consistent across time (Spearman r_s = .88, .76 and .68, two weeks, two years, and 20 years later, respectively), within culture (r_s = .75 and .76, for women and men, respectively), and across cultures (USA and Israel; r_s = .64). Theoretical and practical implications are discussed.     

Should We All be Scientists? Re-thinking Laboratory Research as a Calling

In recent years there have been major shifts in how the role of science—and scientists—are understood. The critical examination of scientific expertise within the field of Science and Technology Studies (STS) are increasingly eroding notions of the “otherness” of scientists. It would seem to suggest that anyone can be a scientist—when provided with the appropriate training and access to data. In contrast, however, ethnographic evidence from the scientific community tells a different story. Scientists are quick to recognize that not everyone can—or should—be a scientist. Appealing to notions such as “good hands” or “gut feelings”, scientists narrate a distinction between good and bad scientists that cannot be reduced to education, access, or opportunity. The key to good science requires scientists to express an intuitive feeling for their discipline, but also that individuals derive considerable personal satisfaction from their work. Discussing this personal joy in—and “fittingness” of—scientific occupations using the fields of STS, ethics and science policy is highly problematic. In this paper we turn to theology discourse to analyze the notion of “callings” as a means of understanding this issue. Callings highlight the identification and examination of individual talents to determine fit occupations for specific persons. Framing science as a calling represents a novel view of research that places the talents and dispositions of individuals and their relationship to the community at the center of flourishing practices.