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81.
Thomas D. Cook William R. Shadish Vivian C. Wong 《Journal of policy analysis and management》2008,27(4):724-750
This paper analyzes 12 recent within‐study comparisons contrasting causal estimates from a randomized experiment with those from an observational study sharing the same treatment group. The aim is to test whether different causal estimates result when a counterfactual group is formed, either with or without random assignment, and when statistical adjustments for selection are made in the group from which random assignment is absent. We identify three studies comparing experiments and regression‐discontinuity (RD) studies. They produce quite comparable causal estimates at points around the RD cutoff. We identify three other studies where the quasi‐experiment involves careful intact group matching on the pretest. Despite the logical possibility of hidden bias in this instance, all three cases also reproduce their experimental estimates, especially if the match is geographically local. We then identify two studies where the treatment and nonrandomized comparison groups manifestly differ at pretest but where the selection process into treatment is completely or very plausibly known. Here too, experimental results are recreated. Two of the remaining studies result in correspondent experimental and nonexperimental results under some circumstances but not others, while two others produce different experimental and nonexperimental estimates, though in each case the observational study was poorly designed and analyzed. Such evidence is more promising than what was achieved in past within‐study comparisons, most involving job training. Reasons for this difference are discussed. © 2008 by the Association for Public Policy Analysis and Management. 相似文献
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Similar to other consumer sectors of the global economy, the transfer of advanced conventional weapons and military technologies has entered the globalization process, a process that has qualitatively and quantitatively altered the composition and structure of U.S. national security policymaking. By injecting the decisionmaking process governing arms transfers into the global market place, U.S. policy makers must now reconcile maintaining economic competitiveness within the global system without jeopardizing U.S. national security interests. By subordinating national security interests to global economic imperatives, U.S. decisionmakers are at risk of mortgaging the political, societal, and security welfare of its citizenry for profit. 相似文献
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This article argues that an Islamist militant group with a relatively homogenous ethnic make-up is more likely to be supported by those of the same ethnicity even if the group makes no reference to and even downplays the importance of ethnicity. Using survey data from an original survey carried out in Pakistan in 2013, with 7,656 respondents, this hypothesis is tested in a multiple regression analysis of support for the Pakistani Taliban. The results demonstrate that co-ethnicity between the respondent and the Islamist militant group is the most important predictor of support for the militant group. 相似文献
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Ayşegül Erdoğan Ph.D. Meral Esen Ph.D. Robin Simpson Ph.D. 《Journal of forensic sciences》2020,65(5):1730-1735
X-ray photoelectron spectroscopy (XPS) is a widely used technique to characterize the surface chemistry of materials. It plays a crucial role in accessing qualitative and quantitative information and in detecting the presence of chemical functional groups on the surface of any material. The forensic methods available to detect and identify elements and organic/inorganic compounds are often destructive, so evidence cannot be re-analyzed. However, XPS allows rapid analysis of samples without damaging them. Recently, an increasing number of forensic researchers have begun to study certain chemical information on fingermarks. In this study, the authors aimed to present the applicability and power of XPS imaging in fingermark analysis which can also provide specific information about the fingermark chemical composition. Herein, monochromated X-ray (Al Kα) spot size was fixed at 50 μm. XPS mapping resulted in the acquisition of spectra at each pixel, in an array of 41 × 30 pixels with a step size of 50 μm. Then, a simple discussion has been made about how the scanned surface spectrum and basic snapshot spectra are used to identify different components at a fingertip of a scanned surface area (~3 mm2). Hence, a fingermark pattern contaminated with caffeine, TiO2, and Pb/PbO deposited on the silicon wafer can be chemically mapped and visualized by XPS using principal component analysis (PCA). Thus, the present study showed the possible applicability of XPS for the identification of illicit drugs of abuse, gunshot residue, and skin care products on latent fingermark by mimicking a crime scene evidence. 相似文献
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William Bernet 《Family Court Review》2020,58(2):362-367
The author wrote an article, “Parental Alienation and Misinformation Proliferation,” for this Special Issue of Family Court Review, which is devoted to various aspects of parental alienation (PA). This short article is a response to the article by Milchman, Geffner, and Meier, which discussed my article and other contributions to the Special Issue. All of these articles represent an attempt by the Editors of the Special Issue to promote “dialogue” among writers who have different perspectives regarding parental alienation. In my view, this is a misguided endeavor, since the publication of cascading criminations, recriminations, and re‐recriminations simply creates confusion and consternation for the readers of Family Court Review. This new article offers an alternative approach for creating constructive dialogue among PA‐promoters and PA‐detractors, that is, convene a face‐to‐face discussion of these individuals and encourage them to write an article together in which they jointly explain their various perspectives regarding PA. 相似文献
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