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Procedures for examining whether treatment effects on an outcome are mediated and/or moderated have been well developed and are routinely applied. The mediation question focuses on the intervening mechanism that produces the treat...
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Procedures for examining whether treatment effects on an outcome are mediated and/or moderated have been well developed and are routinely applied. The mediation question focuses on the intervening mechanism that produces the treatment effect. The moderation question focuses on factors that affect the magnitude of the treatment effect. It is important to note that these two processes may be combined in informative ways, such that moderation is mediated or mediation is moderated. Although some prior literature has discussed these possibilities, their exact definitions and analytic procedures have not been completely articulated. The purpose of this article is to define precisely both mediated moderation and moderated mediation and provide analytic strategies for assessing each.
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We develop a typology of three-way interaction models in order to stimulate more Asia management studies using this approach. In this paper, we explain how to approach moderation based on three-way interactions, introduce three ty...
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We develop a typology of three-way interaction models in order to stimulate more Asia management studies using this approach. In this paper, we explain how to approach moderation based on three-way interactions, introduce three types of three-way interaction models, and provide the appropriate post-hoc statistical procedures accordingly. We also outline several future research examples to demonstrate how three-way interactions can be used in Asian management research.
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Objective The concepts and associated analyses of mediation and moderation are important to the field of psychology. Although pediatric psychologists frequently incorporate mediation and moderation in their theories and empirical ...
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Objective The concepts and associated analyses of mediation and moderation are important to the field of psychology. Although pediatric psychologists frequently incorporate mediation and moderation in their theories and empirical research, on few occasions have we integrated mediation and moderation. In this article, conceptual reasons for integrating mediation and moderation are offered. Method We illustrate a model that integrates mediation and moderation. Results In our illustration, the strength of an indirect or a mediating effect varied as a function of a moderating variable. Conclusions Clinical implications of the integration of mediation and moderation are discussed, as is the potential of integrated models to advance research programs in pediatric psychology.
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This paper describes methods for testing mediation and moderation effects in a dataset, both together and separately. Investigations of this kind are especially valuable in prevention research to obtain information on the process ...
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This paper describes methods for testing mediation and moderation effects in a dataset, both together and separately. Investigations of this kind are especially valuable in prevention research to obtain information on the process by which a program achieves its effects and whether the program is effective for subgroups of individuals. A general model that simultaneously estimates mediation and moderation effects is presented, and the utility of combining the effects into a single model is described. Possible effects of interest in the model are explained, as are statistical methods to assess these effects. The methods are further illustrated in a hypothetical prevention program example.
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Moderators are variables that affect the relationship between a predictor and outcome. They help to clarify otherwise ambiguous patterns of results, extend theory, and signal the growth of a field. Given the importance of moderato...
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Moderators are variables that affect the relationship between a predictor and outcome. They help to clarify otherwise ambiguous patterns of results, extend theory, and signal the growth of a field. Given the importance of moderators, the authors offer an overview of methodological and statistical considerations for testing moderation and then examine sport management scholars' use of moderation in their research. A content analysis of European Sport Management Quarterly, Journal of Sport Management, and Sport Management Review shows that tests of moderation have not followed the growth in scholarship in the field. Further analyses showed (a) analysis of variance was the most popular analytical tool employed; (b) one in six tests of moderation were conducted incorrectly; and (c) 13% of tests for moderation were conducted absent specific hypotheses or research questions. The authors offer implications for sport management researchers.
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A global approach coupling the moderator to the beam extraction system has been applied for the design optimization of the thermal and cold moderators of the European Spallation Source (ESS), which will be the brightest neutron so...
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A global approach coupling the moderator to the beam extraction system has been applied for the design optimization of the thermal and cold moderators of the European Spallation Source (ESS), which will be the brightest neutron source in the world for condensed-matter studies. The design is based on the recently developed high-brightness low-dimensional moderator concepts. Parahydrogen is used for the cold neutron source, while thermal neutrons are provided by moderation in water. The overall moderation configuration was chosen in order to satisfy a range of requirements on bispectral extraction, beamport configuration and instrument performance. All instruments are served by a single moderator assembly above the target, arranged in a 'butterfly' geometry with a height of 3 cm. This was determined to be the optimal height for trade-off between high brightness and efficient guide illumination, by analysis of the performance of 23 instruments, based on the reference suite of the ESS Technical Design Report. The concept of 'brilliance transfer' is introduced to quantify the performance of the neutron optical system from the source to the sample. The target monolith incorporates a grid of 42 neutron beamports with an average separation of 6°, allowing a free choice between cold and thermal neutron sources at all instrument positions.With the large number of beamports and the space below the target available for future moderators, ample opportunities are available for future upgrades.
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The results of testing a cryogenic source of slow monochromatic positrons based on the ~(22)Na isotope, designed and constructed at JINR, are presented. A solid neon moderator was used to generate a monochromatic beam from the con...
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The results of testing a cryogenic source of slow monochromatic positrons based on the ~(22)Na isotope, designed and constructed at JINR, are presented. A solid neon moderator was used to generate a monochromatic beam from the continuous β~± spectrum of 0-0.5 MeV, with solid neon being frozen to the base layer, which is cooled to the temperature of 5-7 K. Test source of the ~(22)Na isotope allows the forming of a slow positron beam of intensity 5.8 x 10~3 part./s and the average energy 1.2 eV at a spectrum width of 1 eV. The efficiency of moderation is 1% of the total positron flux.
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We explore methods for making detailed calculations on the neutronic performance of a pelletised moderator, wherein a significant fraction of the moderating medium is heterogeneously distributed. This pellet approach appears to be...
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We explore methods for making detailed calculations on the neutronic performance of a pelletised moderator, wherein a significant fraction of the moderating medium is heterogeneously distributed. This pellet approach appears to be necessary to provide cooling capabilities to a solid moderator material under heavy heat loads, and furthermore appears to offer the only realistic mechanism for permitting solid moderators in situations where the moderator material stores energy from radiation damage at a significant rate. Current use of solid moderators (e.g. methane at the Intense Pulsed Neutron Source facility) is significantly limited by the need to avoid catastrophic release of this stored energy.
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It is well known from the mediation analysis literature that the identification of direct and indirect effects relies on strong no unmeasured confounding assumptions of no unmeasured confounding. Even in randomized studies the med...
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It is well known from the mediation analysis literature that the identification of direct and indirect effects relies on strong no unmeasured confounding assumptions of no unmeasured confounding. Even in randomized studies the mediator may still be correlated with unobserved prognostic variables that affect the outcome, in which case the mediator's role in the causal process may not be inferred without bias. In the behavioural and social science literature very little attention has been given so far to the causal assumptions required for moderated mediation analysis. In this paper we focus on the index for moderated mediation, which measures by how much the mediated effect is larger or smaller for varying levels of the moderator. We show that in linear models this index can be estimated without bias in the presence of unmeasured common causes of the moderator, mediator and outcome under certain conditions. Importantly, one can thus use the test for moderated mediation to support evidence for mediation under less stringent confounding conditions. We illustrate our findings with data from a randomized experiment assessing the impact of being primed with social deception upon observer responses to others' pain, and from an observational study of individuals who ended a romantic relationship assessing the effect of attachment anxiety during the relationship on mental distress 2years after the break-up.
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This paper examines whether methodological precedence in applying moderation analysis to strategic management research relies on myths and urban legends, and if doing so affected empirical conclusions, implications for theory deve...
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This paper examines whether methodological precedence in applying moderation analysis to strategic management research relies on myths and urban legends, and if doing so affected empirical conclusions, implications for theory development, and practical recommendations. An in-depth analysis of 69 studies published in the Strategic Management Journal between 2000 and 2014 using moderation analysis finds that strategic management scholars typically rely on statistical myths and urban legends when applying moderation analysis including: (1) interpreting main effects separately from their significant interaction with other variables; (2) failing to report reliability values of interaction terms; and (3) relying on hierarchical approaches that can lead to interpretation errors. Further examples illustrate how these practices could lead researchers to draw incomplete and possibly inaccurate conclusions. Overall, problematic precedents have become the gold standards for testing and interpreting moderation models. Best practice recommendations for redirecting future research to more solid methodological grounding are provided.
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