2,070 research outputs found
Type I error and power of the mean and covariance structure confirmatory factor analysis for differential item functioning detection: Methodological issues and resolutions
Recently, mean and covariance structure (MACS) confirmatory factor analysis (CFA) has been widely used to detect items with differential item functioning (DIF). Although how we define the scale does not impact overall model fit or tests for whether or not a given level of measurement equivalence holds, different scaling methods can lead to different conclusions when a researcher locates DIF in a scale. This dissertation evaluates the MACS analysis for DIF detection by means of a Monte Carlo simulation. The simulation results indicate that three statistically equivalent scaling methods provide different outcomes of DIF analysis. In addition, Bonferroni-correction improves the accuracy of the analysis, notably when a scale (or an anchor) is contaminated by DIF. Based on the previous and current simulation studies, this dissertation offers practical guidance for researchers who attempt to evaluate measurement equivalence using CFA
Update on with lattice QCD inputs
We report updated results for , the indirect CP violation
parameter in neutral kaons, which is evaluated directly from the standard model
with lattice QCD inputs. We use lattice QCD inputs to fix ,
, , , , and . Since Lattice 2016,
the UTfit group has updated the Wolfenstein parameters in the angle-only-fit
method, and the HFLAV group has also updated . Our results show that
the evaluation of with exclusive (lattice QCD
inputs) has tension with the experimental value, while that with
inclusive (heavy quark expansion based on OPE and QCD sum rules)
shows no tension.Comment: 8 pages, 7 figures, Lattice 2017 proceeding, references update
Glassy slowdown and replica-symmetry-breaking instantons
Glass-forming liquids exhibit a dramatic dynamical slowdown as the
temperature is lowered. This can be attributed to relaxation proceeding via
large structural rearrangements whose characteristic size increases as the
system cools. These cooperative rearrangements are well modeled by instantons
in a replica effective field theory, with the size of the dominant instanton
encoding the liquid's cavity point-to-set correlation length. Varying the
parameters of the effective theory corresponds to varying the statistics of the
underlying free-energy landscape. We demonstrate that, for a wide range of
parameters, replica-symmetry-breaking instantons dominate. The detailed
structure of the dominant instanton provides a rich window into point-to-set
correlations and glassy dynamics.Comment: 6 pages, 3 figures; v2: narrative revised to clarify our
effective-theoretic viewpoint, results unchanged, added reference
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