Extinction with multiple excitors

Four conditioned suppression experiments with rats, using an ABC renewal design, investigated the effects of compounding the target conditioned excitor with additional, nontarget conditioned excitors during extinction. Experiment 1 showed stronger extinction, as evidenced by less renewal, when the target excitor was extinguished in compound with a second excitor, relative to when it was extinguished with associatively neutral stimuli. Critically, this deepened extinction effect was attenuated (i.e., more renewal occurred) when a third excitor was added during extinction training. This novel demonstration contradicts the predictions of associative learning models based on total error reduction, but it is explicable in terms of a counteraction effect within the framework of the extended comparator hypothesis. The attenuated deepened extinction effect was replicated in Experiments 2a and 3, which also showed that pretraining consisting of weakening the association between the two additional excitors (Experiments 2a and 2b) or weakening the association between one of the additional excitors and the unconditioned stimulus (Experiment 3) attenuated the counteraction effect, thereby resulting in a decrease in responding to the target excitor. These results suggest that more than simple total error reduction determines responding after extinction.     

READINESS AND ATTITUDES AS INDICATORS FOR SUCCESS IN COLLEGE CALCULUS

This study examined student indicators for success in entry-level college calculus. An attitude toward mathematics inventory, course performance, readiness assessment, and student interviews were used to determine characteristics and behaviors of students who succeeded in the course. In addition to student indicators, difficult topics and suggestions for improvement in the course structure were identified. While the focus of this study was on student indicators, the analyses of instructor interviews were included in order to compare their views with those of the students. The quantitative analyses showed that high school grade point average and the Calculus Readiness Assessment had positive significant correlations with course performance. The strongest positive significant correlation, however, was between attitude (Attitudes Toward Mathematics Inventory overall and confidence subscale) and course performance.     

V. CHILDREN NAVIGATING STORIES

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Does generosity beget generosity? Alumni giving and undergraduate financial aid

We investigate how undergraduates’ financial aid packages affect their subsequent donative behavior as alumni. We analyze micro data on alumni giving at an anonymous research university, and focus on three types of financial aid, scholarships, loans, and campus jobs. Consistent with the view of some professional fundraisers, we allow the receipt of a given form of aid per se to affect alumni giving.     

Communicating about gifts of life: the effect of knowledge,attitudes, and altruism on behavior and behavioral intentions regarding organ donation

Much of the limited literature on organ donation has focused on the demographic and psychographic profiles of people who are willing to become organ donors. More information about the relationship of attitudes, values, knowledge, and actual behavior among adults is needed if targeted communication campaigns promoting organ donation are to succeed. The results of a mail survey of 798 adults sampled (via stratified random sampling procedures) from two local sites of a national corporation suggest that attitudes toward donation, knowledge about organ donation, altruism, and perceived social norms are significantly associated with both actual behavior (having signed an organ donor card) and behavioral intent (among non-donors) to sign a card in the future. These findings support the major models of organ donation willingness, especially those advanced by Horton and Horton (1991) and Kopfman (1994). This study also advances current knowledge of organ donation willingness by 1) using a large, relatively diverse population of adults rather than relying on a student sample; and 2) focusing on specific knowledge barriers that distinguish donors from non-donors.     

Young Breast Cancer Survivors’ Experiences of Uncertainty

Evidence indicates recent increases in breast cancer diagnoses among young women. Research also suggests that younger women diagnosed with breast cancer may experience more psychological distress than older women. In-depth interviews with 25 breast cancer survivors age 40 and under were conducted to explore the uncertainties young women face throughout survivorship. Results indicate that young women experience unique sources of uncertainty and that communication may facilitate or hinder the management of uncertainty across the survivorship trajectory. Implications of these findings for theorizing on uncertainty, healthcare providers’ interactions with young women, and social networks’ communication with survivors are discussed. These data also have important implications for the practical treatment of young breast cancer survivors and applied, communicative recommendations for providers are proposed.     

Using Wherry's Adjusted R 2 and Mallow's Cp for Model Selection From All Possible Regressions

Selecting a subset of predictors from a pool of potential predictors continues to be a common problem encountered by applied researchers in education. Because of several limitations associated with stepwise variable selection procedures, the examination of all possible regression solutions has been recommended. The authors evaluated the use of Mallow's C_p and Wherry's adjusted R ² statistics to select a final model from a pool of model solutions. Neither the C_p nor the adjusted R ² statistic correctly identified the underlying regression model any better and was generally worse than the stepwise selection method, which itself was poor. Using any of the model selection procedures studied here resulted in biased estimates of the authentic regression coefficients and underestimation of their standard errors. The use of theory and professional judgment is recommended for the selection of variables in a prediction equation.     

The Utility of Social Attitudes Theory

Kerlinger’s social attitudes theory indicates that attitudes regarding educational practices can be subsumed by the two uncorrelated dimensions, progressivism and traditionalism. This study examined in detail the nature of educators’ education-related attitudes. A stratified sample of 195 students completed two instruments measuring educational attitudes. The results suggest that the already potent explanatory power of Kerlinger’s constructs can be augmented by measuring additional constructs when examining educational phenomena. The results also suggest that Kerlinger’s theoretical principle that social attitudes are dualistic may need to be qualified when the attitudes studied involve the vital roles of subjects.