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The primary claim of the Richiardi et al. (2015) Science article is that a measure of correlated gene expression, significant strength fraction (SSF), is related to resting state fMRI (rsfMRI) networks. However, there is still debate about this claim and whether spatial proximity, in the form of contiguous clusters, accounts entirely, or only partially, for SSF (Pantazatos and Li, 2017; Richiardi et al., 2017). Here, 13 distributed networks were simulated by combining 34 contiguous clusters randomly placed throughout cortex, with resulting edge distance distributions similar to rsfMRI networks. Cluster size was modulated (6-15 mm radius) to test its influence on SSF false positive rate (SSF-FPR) among the simulated \"noise\" networks. The contribution of rsfMRI networks on SSF-FPR was examined by comparing simulated networks whose clusters were sampled from: (1) all 1,777 cortical tissue samples, (2) all samples, but with non-rsfMRI cluster centers, and (3) only 1,276 non-rsfMRI samples. Results show that SSF-FPR is influenced only by cluster size ( > 0.9, < 0.001), not by rsfMRI samples. Simulations using 14 mm radius clusters most resembled rsfMRI networks. When thresholding at < 10 , the SSF-FPR was 0.47. Genes that maximize SF have high spatial autocorrelation. In conclusion, SSF is unrelated to rsfMRI networks. The main conclusion of Richiardi et al. (2015) is based on a finding that is ∼50% likely to be a false positive, not <0.01% as originally reported in the article (Richiardi et al., 2015). We discuss why distance corrections alone and external face validity are insufficient to establish a trustworthy relationship between correlated gene expression measures and rsfMRI networks, and propose more rigorous approaches to preclude common pitfalls in related studies.

The risk attitude plays an important role in analyzing decision making under uncertainty. It is essential to confirm whether the risk aversion parameter in a certain situation, called \"domain,\" can be applied to other situations. Using a dataset on hospitalization insurance policies in Japan, this study tests whether individuals' risk preferences remain consistent across domains. Based on the assumption of expected utility maximizer, we derive a plausible distribution of the degree of risk aversion. We find that degree of risk aversion is consistent between hospitalization benefits and additional insurance for specific diseases. Contrarily, the degree of risk aversion from hospitalization benefits has a negative relationship with that based on a survey question on the self-assessment of general preferences. This result indicates that the imputation of risk aversion from the literature would distort research results markedly if characteristics of the domains targeted by both previous research and this study differ.

Abstract This chapter analyzes a geographic quasi-experiment embedded in a cluster-randomized experiment in Honduras. In the experiment, average treatment effects of conditional cash transfers on school enrollment and child labor were large – especially in the poorest experimental blocks – and could be generalized to a policy-relevant population given the original sample selection criteria. In contrast, the geographic quasi-experiment yielded point estimates that, for two of three dependent variables, were attenuated. A judicious policy analyst without access to the experimental results might have provided misleading advice based on the magnitude of point estimates. We assessed two main explanations for the difference in point estimates, related to external and internal validity.

A recent nationwide cohort study reported an unadjusted Hazard Ratio (HR) of 2.714 for Vitiligo incidence following COVID-19 vaccination, indicating a major safety concern. This finding was based on cohorts with an ≈ 11-year age difference, immediately raising critical concerns regarding extreme structural selection and detection bias. We hypothesize that this extreme association is an artifact of a fatal methodological flaw, challenging the study's internal validity and subsequent external validity. We aim to quantitatively separate the HR attributable to the structural age imbalance (HR Structural) from the residual HR (HR Residual), which quantifies the uncorrected methodological failure and residual confounding. We further perform a plausible recalculation of risk to demonstrate the complete collapse of the risk signal upon correcting the methodological failure in the baseline cohort. We performed a direct age-standardization analysis analysis using the age distribution of the scrutinized study's cohorts (Vaccinated, mean age = 56.32 years vs. Non-Vaccinated, mean age = 45.51 years) and applied established national age-specific Vitiligo incidence rates (IR) from external epidemiology. The HR Structural was calculated to be 1.2104. The remaining HR Residual of 2.2423 quantifies the uncorrected methodological failure. The NV cohort's observed incidence rate (0.67/10,000) was found to be nearly 70% lower than the expected rate (2.2146/10,000), providing quantifiable evidence of profound non-comparability. The subsequent recalculation of risk, correcting for this baseline failure, reduces the observed HR of = 2.714 to an HR Corrected of 1.0025, thus completely annulling the signal of risk due to vaccination. The HR = 2.714 of the scrutinized study is an unstable statistical artifact. The overwhelming majority of the observed association is a consequence of a fatal design flaw. The HR Corrected of almost 1 confirms that correcting the methodological error eliminates the risk signal, demonstrating a severe lack of internal and external validity of the original study.

A broad consensus exists that the use of appropriate methods are important in the Scholarship of Teaching and Learning. However, methodological controversies arise around what constitutes acceptable evidence, if one needs a control group, how generalizable results must be, and other similar issues. Much SoTL work, I argue, asks questions about how much a particular treatment (innovation) caused an effect (student learning), and how the results found in one particular context can be extended outside that context (generalizability). These concepts, known as internal validity and external validity, respectively, provide a common point of departure for much scholarship on teaching and learning. This paper addresses these concepts and demonstrates how they can unite much of what divides us within the methodological realm of SoTL.

The purpose of this study is to discern and discuss issues with relevance to the tension between contextuality and generalisation, which recurrently are identified over time in research reviews of teaching methods. The 75 most cited reviews on teaching methods listed in the Web of Science from 1980 to 2017 were analysed. Since our interest is the claims made in each article about the teaching method under study, the analysis concerned the abstract, results, discussion, conclusion, and implication parts of each review. Three main issues, cutting across the reviews over time, were identified: 1) the abundance of moderating factors, 2) the need for highly qualified teachers, and 3) the research-practice gap. It is argued that the three issues reflect tensions in original research. The implications of these findings are discussed in the article. One main conclusion is that such issues ought to be more explicitly attended to and elaborated in both primary and secondary level research. The importance of viewing validity as a multidimensional concept, including internal, external, and ecological aspects, is underlined. Further, ideas from realistic reviewing are used to discuss a contextually bound approach to causality.

Replication crisis and debates about p-values have raised doubts about what we can statistically infer from research findings, both in experimental and observational studies. With a view to the ongoing debate on inferential errors, this paper systematizes and discusses experimental designs with regard to the inferences that can and - perhaps more important - that cannot be made from particular designs.

Orientation: Psychological capital (PsyCap) is a relatively novel construct measured with the Psychological Capital Questionnaire 24 (PCQ-24). Only one published South African study on the instrument exists, providing inconsistent psychometric results, when compared with other United States of America (USA) and non-USA studies.Research purpose: The objectives of this study were to investigate the internal validity (construct and discriminant validity), reliability and external validity (relationship with theoretically relevant variables, namely stress, burnout and work engagement) of the PCQ-24.Motivation for the study: Multiple studies have underscored the value of PsyCap within the workplace. In order to harness the full potential of the construct in the South African environment, sound measurement thereof, evidenced by a psychometrically sound instrument, is needed.Research design, approach and method: A cross-sectional survey design was used. The sample consisted of employees at managerial and non-managerial levels, from a medium-sized construction company in the Western Cape, South Africa. In addition to PsyCap, perceived stress, work-related burnout and work engagement were measured.Main findings: The results provided preliminary evidence of construct and discriminant validity, reliability and significant relations with external theoretically relevant variables.Practical/managerial implications: Researchers may confidently use the PCQ-24 to measure the construct of PsyCap and investigate relations with workplace outcomes in the South African environment, informing human relations practices.Contribution/value-add: Preliminary evidence of the psychometric properties of the PCQ-24, which measures the construct of PsyCap (consisting of hope, self-efficacy, resilience and optimism) on a South African sample, was provided in this study.

Background This paper attempts to evaluate the primary health care system by evaluating health centres in Greece. Methods Malmquist Index Data Envelopment Analysis is applied to study the total productivity of 155 health centres in Greece during 2016–2018. The data were collected from the Ministry of Health and submitted to quality tests to ensure validity and avoid bias. Results This paper measures the productivity of each of the 155 health centres in Greece and how it shifted during 2016–2018. In addition, the overall productivity change of the 155 health centres over time is calculated and analysed as being due to technical efficiency or technological efficiency. The analysis of the mean values showed a decrease of 0.9% in the overall productivity factor from 2016 to 2017 and a decrease of 5.2% from 2017 to 2018. The overall decrease in the productivity of the 155 health centres was 3.1%. From 2016 to 2018, 59 health centres changed their productivity mainly due to technological change and 91 changed mainly due to technical efficiency change. One health centre showed regression to its total productivity due to equal regression of its technical efficiency and technology. Conclusions The method used is nonparametric data envelopment analysis along with the Malmquist index to include panel data in the analysis. Meaningful results were extracted by indicating the number of health centres that improved their productivity, regressed in productivity, or remained constant through the period 2016–2018. This paper may contribute to improving health centres’ efficiency and productivity. Furthermore, valuable results can be extracted for the National Health Care System to match available resources that correspond to each health centre’s needs, as well as for manager planners and stakeholders in primary health care.

We used elective total joint replacement (TJR) as a case study to demonstrate selection bias toward offering this procedure to younger and healthier patients. Longitudinal data from 2,202 men were integrated with hospital data and mortality records. Study participants were followed from recruitment (1996–1999) until TJR, death, or 2007 (end of follow-up). A propensity score (PS) was constructed to quantify each subject's likelihood of undergoing TJR. TJR recipients were later matched to their non-TJR counterparts by PS and year of hospitalization. Ten-year mortality from index admission was compared between cases and controls. Overall, 819 (37.2%) had TJR. Those were younger, healthier, and belonged to higher socioeconomic classes compared with those who were not proposed for surgery. Of the TJR recipients, 718 were matched to 1,109 controls. Cases and controls had similar characteristics and similar years of follow-up from recruitment till index admission. Nonetheless, controls were more likely to die (39.5%) compared with 14.5% in TJR cases (P < 0.001). Selection for elective procedures may introduce bias in prognostic features not accounted for by PS matching. Caution must be exercised when long-term outcomes are compared between surgical and nonsurgical groups in a population at risk for that surgical procedure.