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Veranstaltungen am 04.02.2019:

Prof. Dr. Riccardo De Bin, University of Oslo, Department of Mathematics:
Detection of influential points as a byproduct of resampling‐based variable selection procedures
Influential points can cause severe problems when deriving a multivariable regression
model. A novel approach to check for such points is proposed, based on the variable inclusion matrix,
a simple way to summarize results from resampling‐based variable selection procedures. These
procedures rely on the variable inclusion matrix, which reports whether a variable (column) is
included in a regression model fitted on a pseudo‐sample (row) generated from the original data
(e.g., bootstrap sample or subsample). The variable inclusion matrix is used to study the variable
selection stability, to derive weights for model averaged predictors and in others investigations.
Concentrating on variable selection, it also allows understanding whether the presence of a specific
observation has an influence on the selection of a variable. From the variable inclusion matrix,
indeed, the inclusion frequency (I‐frequency) of each variable can be computed only in the pseudosamples
(i.e., rows) which contain the specific observation. When the procedure is repeated for each
observation, it is possible to check for influential points through the distribution of the I‐frequencies,
visualized in a boxplot, or through a Grubbs' test. Outlying values in the former case and significant
results in the latter point to observations having an influence on the selection of a specific variable
and therefore on the finally selected model. This novel approach is illustrated in two real data
examples.
04.02.2019 16:15 - 17:45, Hörsaal IMBI, Stefan-Meier-Straße 26
Julia Bonaccorsi, Lyon:
Juger en commun l'inacceptable par la documentation photographique : le cas de la campagne #SoyonsHumains
Vortrag im Rahmen des Forschungskolloquiums am Frankreich-Zentrum

En décembre 2017, une campagne participative d'inventaire photographique des « mobiliers urbains anti-SDF » est initiée par la Fondation Abbé Pierre et Emmaüs Solidarité à partir du hashtag #SoyonsHumain. Il s'agira à partir de ce cas d'étude de nous intéresser à la médiatisation en jeu pour rendre lisible et visible une dimension non perçue de l'espace public, et de prolonger la réflexion engagée par Luc Boltanski à propos de la souffrance à distance. Notamment, nous rendrons compte des différentes opérations de mise en discours de la « cause de l'autre » et le rôle de spectateur-témoin que cette campagne définit.
04.02.2019 19:00 - 21:00, R 101, Breisacher Tor, Rempartstr. 4
Tel: 0761/203-2008
Fax: 0761/203-2006