[Forum SIS] University of Perugia: upcoming seminars of Prof. Tenko Raykov (Michigan State University)

[gnaldi a stat.unipg.it]

Dear All,
We are glad to announce two upcoming seminars of Professor Tenko Raykov
(Michigan State University) at the University of Perugia. Please, see
below for details.

Best regards,
Michela Gnaldi and Silvia Bacci

*********************************************************************************
April 7th 2016, 4.00pm – Department of Political Sciences – University of
Perugia
*********************************************************************************

Scale Construction and Development in Political Science Research Using
Latent Variable Modeling

Abstract
This talk is concerned with applications of the increasingly popular
latent variable modeling methodology in scale construction and development
in political and social science research. A unified framework is initially
outlined that is based on use of latent variables of main concern in
empirical research. Classical test theory, factor analysis, and item
response theory are then shown to be (essentially) special cases of this
general methodological approach. Procedures for development of improved
measuring instruments consisting of multiple components are subsequently
outlined within this framework. The discussed approach allows obtaining
optimal point and interval estimates of relevant parameters. This general
method can be used as a guide by empirical political and social
researchers toward developing revised versions of initially considered
scales/measuring instruments with enhanced psychometric properties, and is
illustrated throughout using conceptual and numerical examples.
Keywords: classical test theory, factor analysis, item response theory,
latent variable modeling, measurement, measuring instrument, scale,
reliability, validity

*************************************************************************
April 8th 2016, 12.00am – Department of Economics – University of Perugia
*************************************************************************

On Latent Change Model Choice in Longitudinal Studies

Abstract
This talk is concerned with two helpful aids in the process of choosing
between models of change in repeated measure investigations in the
behavioral and social sciences: (i) interval estimates of proportions
explained variance in longitudinally followed variables, and (ii)
individual case residuals associated with these measures. The discussed
method allows obtaining confidence intervals for the R-squared indices of
repeatedly administered measures, as well as subject-specific
discrepancies between model predictions and raw data on the observed
variables. In addition to facilitating evaluation of local model fit, the
approach is useful for the purpose of differentiating between plausible
models stipulating different patterns of change over time. This feature of
the described method becomes particularly helpful in empirical situations
characterized by (very) large samples and high statistical power, which
are becoming increasingly more frequent in complex sample design studies
in the behavioral, health, marketing, and social sciences. The approach is
similarly applicable in cross-sectional investigations, as well as with
general structural equation models, and extends the set of means available
to substantive researchers and methodologists for model fit evaluation
beyond the traditionally used overall goodness of fit indexes. The
discussed method is illustrated using data from a nationally
representative study of older adults.
Keywords: confidence interval, individual case residual, latent growth
curve modeling, overall fit index, local fit index, linear model, model
choice, model fit, non-linear model, significance.


-- 
Michela Gnaldi
Assistant Professor in Social Statistics
Department of Political Sciences
University of Perugia
e-mail: michela.gnaldi a stat.unipg.it
            michela.gnaldi a unipg.it
Phone: (0039) 075 585 5240