Implicit Assumption Research Articles

Nonparametric identification of causal effects in clustered observational studies with differential selection

Abstract The clustered observational study (COS) design is the observational counterpart to the clustered randomized trial. COSs are common in both education and health services research. In education, treatments may be given to all students within some schools but withheld from all students in other schools. In health studies, treatments may be applied to clusters such as hospitals or groups of patients treated by the same physician. In this paper, we study the identification of causal effects in COS designs. We focus on the prospect of differential selection of units to clusters, which occurs when the units’ cluster selections depend on the clusters’ treatment assignments. Extant work on COSs has made an implicit assumption that rules out the presence of differential selection. We derive the identification results for designs with differential selection and that contexts with differential cluster selection require different adjustment sets than standard designs. We outline estimators for designs with and without differential selection. Using a series of simulations, we outline the magnitude of the bias that can occur with differential selection. We then present 2 empirical applications focusing on the likelihood of differential selection.

How does population size influence administrative performance? Evidence from Malta, Samoa, and Suriname

Public administration scholars pay increasing attention to the role of context as a pathway to genuinely comparative analysis. Specifically, they focus on the economic, institutional and socio-cultural conditions in which administration takes place. Population size is an overlooked contextual factor despite the fact that existing studies often make implicit, positive assumptions about the effects of smallness on administrative performance. We investigate these assumptions by focusing on small, rather than large states across three dimensions: representativeness, transparency and service delivery. Drawing on unique qualitative data from three small states from different continents, Malta, Samoa and Suriname, we find that contra implicit assumptions, small population size does not have the overwhelmingly positive effects that much of the literature assumes. Rather, smallness tends to undermine legal-rational decision making and to facilitate patronage-based service delivery. These findings indicate that the contextual turn in public administration needs to pay more attention to the way population size shapes bureaucratic practice in all states, large and small.

Colonial Redress and the Unintended Consequences of Global Opportunities

Abstract Research shows that the rise of political and discursive opportunities enabled by the diffusion of progressive global norms has empowered many aggrieved local actors. Drawing on colonial victims’ transnational redress movements, I add to this literature in two ways. First, rejecting the common association between global opportunities and local movement facilitation and success, I make a counterintuitive argument that the early availability of opportunities can inadvertently hamper a movement’s efficacy in achieving its goals in the long run. Second, contrary to the implicit assumption that large-scale, high-profile transnational movements should fare better than smaller, little-known ones, I demonstrate that the latter can sometimes achieve their goals more easily than the former. In making these arguments, I show that an increasing focus in the norm literature on backlash in target states against norm promotion risks neglecting the flip side of the same coin: Global normative support inadvertently undermining the efficacy of local causes it otherwise helps publicize. Empirically, I look at three Korean colonial victim groups and their divergent paths to transnational redress.

The Puzzling of Stefan–Boltzmann Law: Classical or Quantum Physics

Stefan–Boltzmann law, stating the fourth power temperature dependence of the radiation emission by a black-body, was empirically formulated by Stefan in 1874 by fitting existing experiments and theoretically validated by Boltzmann in 1884 on the basis of a classical physical model involving thermodynamics principles and the radiation pressure predicted by Maxwell equations. At first sight the electromagnetic (EM) gas assumed by Boltzmann and following Rayleigh (1900) identifiable as an ensemble of N classical normal-modes, looks like an extension of the classical model of the massive ideal-gas. Accordingly, for this EM gas the internal total energy, U, was assumed to be function of volume V and temperature T as [Formula: see text], and the equation of state was given by [Formula: see text], with P the radiation pressure. In addition, Boltzmann implicitly assumed that, for given values of V and T, U and the number of modes N would take finite values. However, from one hand these assumptions are not justified by Maxwell equations and classical statistics since, in vacuum (i.e., far from the EM sources), the values of N and U diverge, the so-called ultraviolet catastrophe introduced by Ehrenfest in 1911. From another hand, Boltzmann derivation of Stefan law is found to be macroscopically compatible with its derivation from quantum statistics announced by Planck in 1901. In this paper, we present a justification of this puzzling classical/quantum compatibility by noticing that the implicit assumptions made by Boltzmann is fully justified by Planck quantum statistics. Furthermore, we shed new light on the interpretation of recent classical simulations of a black body carried out by Wang, Casati, and Benenti in 2022 who found an analogous puzzling consistency between Stefan–Boltzmann law and their simulations to induce speculations on classical physics and black body radiation that are claimed to require a critical reconsideration of the role of classical physics for the understanding of quantum mechanics.

The concept of banking capital risk-sensitivity revisited

The article studies the foundations of the risk-sensitivity concept of regulatory banking capital. The author states that risk of losses, including unexpected ones covered in accordance with the concept by banking capital cannot be measured with satisfactory accuracy. This is the principal obstacle to the concept implementation. The efficacy of Basel III capital regime with parallel use of risk-sensitive and risk-insensitive approaches is under scrutiny. Rationales are adduced that under this regime risk-sensitive approach has no real value. The study of risk-sensitive approach abilities among macro-prudential tools leads to the conclusion that its efficiency is apparently insufficient. The analysis of the academic study on the issue is carried out. This research recommends to impose risk-sensitive capital requirements if the risk of bank assets can be measured quite accurately. It is shown that the study is based on the implicit assumption of the absence of unexpected losses phenomenon in banking activity. This assumption is unrealistic and makes research in effect objectless. The major inference from the study is that the regulatory capital risk-sensitivity concept is not well-founded and its use for capital adequacy regulation is inadvisable. For micro-prudential purposes the simple leverage deems more expedient. It is capable to ensure for capital regulation the reasonable balance of risk-sensitivity to failure, simplicity and comparability.

Utilizing Artificial Neural Networks for Entry Vehicle Aerodynamic Characterization

Determining the dynamic stability of blunt body entry vehicles is a persistent engineering challenge, particularly in the low supersonic to subsonic flight regime where the behavior of the unsteady wake is a primary contributor. Dynamic stability quantities are determined by fitting measurements of a ballistic range campaign or a computational fluid dynamics (CFD) computational experiment to an assumed functional form in order to regress quasi-static stability coefficients. However, this data reduction process has many implicit assumptions that may not hold. This paper explores novel alternatives to the established methods for modeling blunt body aerodynamics. A six-degree-of-freedom CFD-in-the-loop flight model is used to run “virtual ballistic range tests,” fully capturing the relevant flow physics. Feed-forward and time-delay neural network models are fitted to the time-series trajectory and aerodynamic results, which can then be used to predict aerodynamic forces and moments. These models do not have a prescribed functional form and do not assume linearized aerodynamics. The models are evaluated for goodness-of-fit in their aerodynamic and trajectory prediction. The feed-forward neural network model resulted in a better prediction of the virtual ballistic range tests than a traditional database. The time-delay network had good open-loop performance but suffered from closed-loop instability.

Competition for time: Evidence for an overlooked, diversity-maintaining competitive mechanism.

Understanding how diversity is maintained in plant communities requires that we first understand the mechanisms of competition for limiting resources. In ecology, there is an underappreciated but fundamental distinction between systems in which the depletion of limiting resources reduces the growth rates of competitors and systems in which resource depletion reduces the time available for competitors to grow, a mechanism we call 'competition for time'. Importantly, modern community ecology and our framing of the coexistence problem are built on the implicit assumption that competition reduces the growth rate. However, recent theoretical work suggests competition for time may be the predominant competitive mechanism in a broad array of natural communities, a significant advance given that when species compete for time, diversity-maintaining trade-offs emerge organically. In this study, we first introduce competition for time conceptually using a simple model of interacting species. Then, we perform an experiment in a Mediterranean annual grassland to determine whether competition for time is an important competitive mechanism in a field system. Indeed, we find that species respond to increased competition through reductions in their lifespan rather than their rate of growth. In total, our study suggests competition for time may be overlooked as a mechanism of biodiversity maintenance.

Active and passive virtual machine introspection on AMD and ARM processors

Active and passive virtual machine introspection mechanisms are pivotal for monitoring virtual machines on top of a hypervisor. They enable external tools to monitor and inspect the state from the outside. Active virtual machine introspection mechanisms intercept the execution at predetermined locations of interest synchronous to the execution of the system. Such mechanisms, in particular, require support from the processor vendor by facilitating interpositioning. This support is missing on AMD x86 processors, leading to inferior introspection solutions. We outline implicit assumptions about active introspection mechanisms in previous work, offer constructions for solution strategies on AMD systems, and discuss stealthiness and correctness. We show empirically that such retrofitted software solutions exhibit performance metrics in the same order of magnitude as native hardware solutions. Moreover, we highlight that the open problems for virtual machine introspection on ARM systems and those encountered on AMD x86 are related. Hence, we present an introspection architecture based on KVMi that addresses these open problems. Finally, we demonstrate comparable and, in many cases, superior performance to state-of-the-art solutions on Intel x86.

Where is the panic in “panic buying”? Consumer purchases at the outset of the COVID pandemic

The declaration of the COVID pandemic in March 2020 was immediately followed by news media accounts of “panic buying.” However, this term is problematic because it implicitly assumes that people engage in indiscriminate consumer product purchases that are motivated solely by extreme fear. Contrary to the implicit assumptions of “panic buying,” this study's examination of consumer product purchases by 435 households found that respondents drew clear distinctions among four activities (observed shortages, own consumption changes, own stockpiling, and others’ stockpiling) related to six consumer product categories (fresh produce, fresh meat, nonperishable food, cleaning supplies, sanitary supplies, and nonprescription medications). The results show that own stockpiling has moderately positive correlations with own consumption changes and is as strongly related to optimism and anger as to fear. Own stockpiling also has positive correlations with perceptions of others’ stockpiling, reliance on informal information sources, and observed shortages. Unexpectedly, own stockpiling has positive correlations with positive disaster stereotypes rather than negative disaster stereotypes, and is unrelated to expected pandemic duration, authoritative information sources, demographic characteristics, and routine stockpiling. The results suggest that the term “panic buying” should be replaced by “crisis stockpiling,” which avoids unnecessary erroneous inferences about the motivation for that behavior.

Abdication of Responsibility for Father–Child Contact in a Group of Black South African Non-resident Father Families: A Systems Perspective

Much of what is known about non-resident fathers is based on studies conducted in North America and Europe, and on the accounts of only one family member. This article draws from a study which utilised a family systems perspective and obtained the views of four members of ten Black South African non-resident father families ( N = 40) with infrequent father–child contact. The aim was to investigate if and how non-resident fathers’ contact with adolescent children was influenced by relationships with various family members. Individual interviews were conducted with each of the family member and thematically analysed. Here, we engage with one of the master themes that shows the circular dynamic in families in which various family members held implicit assumptions about who was responsible for father–child contact and, subsequently, did not view the responsibility to be theirs. Infrequent or lack of non-resident father–child contact should therefore be addressed as a family systems issue.

Shadows or Forgeries? Explaining Legal Normativity

Abstract Legal norms serve as practical standards for individuals and officials. While this ‘normative aspect’ of law is widely acknowledged, its significance for theories of law remains contested. In this paper, I examine three views on the matter. First, that we should explain legal norms as reason-giving. Second, that we should explain legal discourse as being about reasons for action. Third, that we should explain law as capable of being reason-giving. I survey some challenges associated with each of these views. What they have in common is an implicit assumption about the form that normative explanation must take: that it must be a linear, non-reductive explanation. There is an alternative model for normative explanation available, however. That model explains normative notions in terms of the practices and attitudes involved in recognizing, offering, and demanding them. I highlight the potentials, and limitations, of this practice-centered alternative.

A comprehensive review and shiny application on the matching-adjusted indirect comparison.

Population-adjusted indirect comparison (PAIC) is an increasingly used technique for estimating the comparative effectiveness of different treatments for the health technology assessments when head-to-head trials are unavailable. Three commonly used PAIC methods include matching-adjusted indirect comparison (MAIC), simulated treatment comparison (STC), and multilevel network meta-regression (ML-NMR). MAIC enables researchers to achieve balanced covariate distribution across two independent trials when individual participant data are only available in one trial. In this article, we provide a comprehensive review of the MAIC methods, including their theoretical derivation, implicit assumptions, and connection to calibration estimation in survey sampling. We discuss the nuances between anchored and unanchored MAIC, as well as their required assumptions. Furthermore, we implement various MAIC methods in a user-friendly R Shiny application Shiny-MAIC. To our knowledge, it is the first Shiny application that implements various MAIC methods. The Shiny-MAIC application offers choice between anchored or unanchored MAIC, choice among different types of covariates and outcomes, and two variance estimators including bootstrap and robust standard errors. An example with simulated data is provided to demonstrate the utility of the Shiny-MAIC application, enabling a user-friendly approach conducting MAIC for healthcare decision-making. The Shiny-MAIC is freely available through the link: https://ziren.shinyapps.io/Shiny_MAIC/.

Capturing individual differences in sentence processing: How reliable is the self-paced reading task?

Advances in research on language processing have originally come from group-level comparisons, but there is now a growing interest in individual differences. To investigate individual differences, tasks that have shown robust group-level differences are often used with the implicit assumption that they will also be reliable when used as an individual differences measure. Here, we examined whether one of the primary tasks used in psycholinguistic research on language processing, the self-paced reading task, can reliably measure individual differences in relative clause processing. We replicated the well-established effects of relative clauses at the group level, with object relative clauses being more difficult to process than subject relative clauses. However, when using difference scores, the reliability of the size of the relative clause effect was close to zero because the self-paced reading times for the different relative clause types were highly correlated within individuals. Nonetheless, we found that the self-paced reading task can be used to reliably capture individual differences in overall reading speed as well as key sentence regions when the two types of relative clause sentences are considered separately. Our results indicate that both the reliability and validity of different sentence regions need to be assessed to determine whether and when self-paced reading can be used to examine individual differences in language processing.

Disaggregation of humanitarian data by disability: a realist evaluation of the use of the Washington Group Questions to support more inclusive practices

AbstractPeople with disabilities make up approximately 16% of the world’s population and disproportionately experience the risks and negative impacts of humanitarian emergencies. In humanitarian contexts, understanding who has a disability, where they are located, and what their needs are is crucial to delivering the right assistance at the right place and time. In recent years, global attention to disability inclusion in the humanitarian sector has focused on the generation of disaggregated data, most commonly using one of the Washington Group Sets of Questions. The implicit assumption behind the collection of more and more data disaggregated by disability, that it will lead to more inclusive action and outcomes, is incorrect. Our findings nuance the current push for disability disaggregated data in all settings and advocate a shift away from the blanket application of disaggregation to a more bespoke approach. Humanitarian and development contexts present multiple challenges to disaggregating data sets by demographic factors such as disability, including the use of households rather than individuals as the unit of analysis, small and non-representative samples, and minority languages with limited translation capacity. Through evaluation of the use of the Washington Group set across the world’s largest humanitarian organization, and its cooperating partners, we present five decision-making criteria that can be flexibly but consistently applied across operating contexts. This enables contextualized decision-making that uses consistent logic to predict the likelihood of data disaggregation by disability leading to more inclusive action and outcomes.

How getting in sync is curative: Insights gained from research in psychotherapy.

We are all constantly going in and out of sync with the people we meet in our lives: significant others, incidental encounters, and strangers. Synchrony is a ubiquitous phenomenon, considered an evolution-based mechanism of survival. In recent years, technological development has made it possible to collect much data on synchrony across disciplines. The collected data show great potential to shed light on the benefits of this universal phenomenon. At the same time, mixed results emerged, stressing the need for a theory to navigate research inquiries and discoveries. It is proposed here that synchrony serves as an individual-specific mechanism for making relationships curative in all life circumstances, especially therapeutic ones-hence its special relevance for psychotherapy. A synthesis of the majority of the literature across disciplines reveals two implicit assumptions about synchrony, resulting in two separate bodies of knowledge: (a) synchrony is a trait-like signature characterizing individuals; and (b) synchrony is a state-like phenomenon that can be manipulated in the lab. It is proposed here to personalize synchrony research by integrating the two assumptions into a comprehensive theory according to which individuals have a trait-like signature for getting in sync, which determines their physical and mental health, and that this deterministic reality can be subject to state-like manipulation. Individuals can deviate from their trait-like signature. When the deviation is toward normative activation, mental health improves, and the state-like changes are defined as therapeutic. This article calls for research to investigate how trait-like signature of synchrony develops and how it can be therapeutically changed. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Exit (digital) humanity: Critical notes on the anthropological foundations of “digital humanism”

This paper evaluates the historical-anthropological and ethical underpinnings of the concept of “digital humanism.” Our inquiry begins with a reconstructive analysis, focusing on three pivotal works defining digital humanism. The objective is to expose shared characteristics shaping the notions of “human being” and “humanity.” Moving forward, our investigation employs anthropological-evolutionary and individual-cognitive perspectives to discern how cultural-historical contingencies shape the implicit understanding of the “human being” that forms the foundation for digital humanism. As an illustrative case study, we delve into Luddism to illuminate the potential and limitations of adopting a critical stance towards digital humanism. Through a thorough analysis, encompassing both efficacy and implicit anthropological elements, our goal is to extract ethical implications pertinent to our broader objective. This examination reveals the interplay between cultural-historical contingencies and anthropological constants in shaping assumptions about the “human being” within the context of digital humanism. In conclusion, our paper contributes to a nuanced understanding of the implicit assumptions permeating the digital humanism discourse. We advocate for a more critical and reflective engagement with the foundational concepts of digital humanism, urging scholars and practitioners to navigate the complexities of its historical-anthropological and ethical dimensions.

The politics of China's policy processes: A comparative review of the Advocacy Coalition Framework's applications to mainland China

AbstractDrawing on a review of 112 Advocacy Coalition Framework (ACF) applications to China published during 2006–2022, this article finds that, consistent with ACF assumptions, policy processes in China are complex processes of top‐down decision making, horizontal negotiation, networked influence, and bottom‐up initiation. The review finds policy processes in many subsystems of China inconsistent with one implicit assumption of the framework: the difficulty of reconciling conflicting beliefs between warring coalitions. Compared with the results from a review of the English ACF applications to countries around the globe, policy‐oriented learning and imposition by a hierarchically superior jurisdiction were identified more frequently as pathways to policy change in reviewed applications to China. The Xi Jinping administration encourages between‐coalition learning and negotiation to pursue the ideal of building a well‐off and equitable society. At the same time, his top‐level reforms have changed the long‐time status quo in some subsystems by national policy reforms.Related ArticlesNam, Aerang, and Christopher M. Weible. 2023. “Examining Experts' Discourse in South Korea's Nuclear Power Policy Making: An Advocacy Coalition Framework Approach to Policy Knowledge.” Politics & Policy 51(2): 201–21. https://doi.org/10.1111/polp.12522.Nwalie, Martin Ike. 2019. “Advocacy Coalition Framework and Policy Changes in a Third‐World Country.” Politics & Policy 47(3): 545–68. https://doi.org/10.1111/polp.12302.von Malmborg, Fredrik. 2023. “Combining the Advocacy Coalition Framework and Argumentative Discourse Analysis: The Case of the ‘Energy Efficiency First’ Principle in EU Energy and Climate Policy.” Politics & Policy 51(2): 222–41. https://doi.org/10.1111/polp.12525.

Beyond Population-Level Targets for Drug Concentrations: Precision Dosing Needs Individual-Level Targets that Include Superior Biomarkers of Drug Responses.

The purpose of precision dosing is to increase the chances of therapeutic success in individual patients. This is achieved in practice by adjusting doses to reach precision dosing targets determined previously in relevant populations, ideally with robust supportive evidence showing improved clinical outcomes compared with standard dosing. But is this implicit assumption of translatable population-level precision dosing targets correct and the best for all patients? In this review, the types of precision dosing targets and how they are determined are outlined, problems with the translatability of these targets to individual patients are identified, and ways forward to address these challengers are proposed. Achieving improved clinical outcomes to support precision dosing over standard dosing is currently hampered by applying population-level targets to all patients. Just as "one-dose-fits-all" may be an inappropriate philosophy for drug treatment overall, a "one-target-fits-all" philosophy may limit the broad clinical benefits of precision dosing. Defining individual-level precision dosing targets may be needed for greatest therapeutic success. Superior future precision dosing targets will integrate several biomarkers that together account for the multiple sources of drug response variability.

Investigating the reliability of aggregate measurements of learning process data: From theory to practice

AbstractBackgroundLearning analytics (LA) research often aggregates learning process data to extract measurements indicating constructs of interest. However, the warranty that such aggregation will produce reliable measurements has not been explicitly examined. The reliability evidence of aggregate measurements has rarely been reported, leaving an implicit assumption that such measurements are free of errors.ObjectivesThis study addresses these gaps by investigating the psychometric pros and cons of aggregate measurements.MethodsThis study proposes a framework for aggregating process data, which includes the conditions where aggregation is appropriate, and a guideline for selecting the proper reliability evidence and the computing procedure. We support and demonstrate the framework by analysing undergraduates' academic procrastination and programming proficiency in an introductory computer science course.Results and ConclusionAggregation over a period is acceptable and may improve measurement reliability only if the construct of interest is stable during the period. Otherwise, aggregation may mask meaningful changes in behaviours and should be avoided. While selecting the type of reliability evidence, a critical question is whether process data can be regarded as repeated measurements. Another question is whether the lengths of processes are unequal and individual events are unreliable. If the answer to the second question is no, segmenting each process into a fixed number of bins assists in computing the reliability coefficient.Major TakeawaysThe proposed framework can be a general guideline for aggregating process data in LA research. Researchers should check and report the reliability evidence for aggregate measurements before the ensuing interpretation.

Effects of group size and population size on the evolutionary stability of cooperation

Evolutionary game theory has classically been developed under the implicit assumption of an infinite population. Exact analytical results for finite populations are rare, and those that exist apply to situations in which strategy sets are discrete. We rigorously analyse a standard model for the evolution of cooperation (the multi-player continuous-strategy snowdrift game) and show that in many situations in which there is a cooperative evolutionarily stable strategy (ESS) if the population is infinite , there is no cooperative ESS if the population is finite (no matter how large). In these cases, contributing nothing is a globally convergently stable finite-population ESS, implying that apparent evolution of cooperation in such games is an artefact of the infinite population approximation. The key issue is that if the size of groups that play the game exceeds a critical proportion of the population then the infinite-population approximation predicts the wrong evolutionary outcome (in addition, the critical proportion itself depends on the population size). Our results are robust to the underlying selection process.