Results 31 to 40 of about 1,714,069 (326)

Multiple Imputation Ensembles (MIE) for dealing with missing data [PDF]

, 2020
Missing data is a significant issue in many real-world datasets, yet there are no robust methods for dealing with it appropriately. In this paper, we propose a robust approach to dealing with missing data in classification problems: Multiple Imputation ...
A Farhangfar, AM Sefidian, B Schölkopf, C Cortes, CT Tran, DA Newman, DB Rubin, DB Rubin, DH Wolpert, EL Silva-Ramírez, GE Batista, GJ van der Heijden, H Gao, IH Witten, J Demšar, J Honaker, J Honaker, J Scheffer, JA Sterne, JL Schafer, JL Schafer, JR Quinlan, K Abayomi, KM Ting, L Breiman, L Breiman, L Rokach, M Fichman, M Khalilia, M Spratt, MA Klebanoff, MJ Azur, NJ Horton, PJ García-Laencina, PJ Kelly, PN Tan, RJ Little, S García, S Van Buuren, S Van Buuren, SS Chae, SS Choi, U Garciarena, V Vapnik, X Chen, Y Dong, Y Freund, Y He, Z Che, Z Liu   +49 more
core   +1 more source

On using a non-probability sample for the estimation of population parameters

Lietuvos Matematikos Rinkinys, 2023
We aim to find a way to effectively integrate a non-probability (voluntary) sample under the data framework, where the study variable is also observed in a probability sample of some statistical survey.
Ieva Burakauskaitė, Andrius Čiginas
doaj   +3 more sources

An application of a pattern-mixture model with multiple imputation for the analysis of longitudinal trials with protocol deviations

BMC Medical Research Methodology, 2019
Background The benefit of a given treatment can be evaluated via a randomized clinical trial design. However, protocol deviations may severely compromise treatment effect since such deviations often lead to missing values.
Abdul-Karim Iddrisu, Freedom Gumedze
doaj   +1 more source

Spontaneous breaking of rotational symmetry in the presence of defects [PDF]

, 2013
We prove a strong form of spontaneous breaking of rotational symmetry for a simple model of two-dimensional crystals with random defects in thermal equilibrium at low temperature.
Heydenreich, Markus, Merkl, Franz, Rolles, Silke W. W.   +2 more
core   +2 more sources

Imputation strategies when a continuous outcome is to be dichotomized for responder analysis: a simulation study

BMC Medical Research Methodology, 2019
Background In many clinical trials continuous outcomes are dichotomized to compare proportions of patients who respond. A common and recommended approach to handling missing data in responder analysis is to impute as non-responders, despite known biases.
Lysbeth Floden, Melanie L. Bell
doaj   +1 more source

Little's Test of Missing Completely at Random [PDF]

The Stata Journal: Promoting communications on statistics and Stata, 2013
In missing-data analysis, Little's test (1988, Journal of the American Statistical Association 83: 1198–1202) is useful for testing the assumption of missing completely at random for multivariate, partially observed quantitative data. I introduce the mcartest command, which implements Little's missing completely at random test and its extension for ...
Li, Cheng, Li, Cheng
openaire   +2 more sources

Comparison of Different LGM-Based Methods with MAR and MNAR Dropout Data

Frontiers in Psychology, 2017
The missing not at random (MNAR) mechanism may bias parameter estimates and even distort study results. This study compared the maximum likelihood (ML) selection model based on missing at random (MAR) mechanism and the Diggle–Kenward selection model ...
Meijuan Li, Meijuan Li, Nan Chen, Yang Cui, Hongyun Liu, Hongyun Liu   +5 more
doaj   +1 more source

Investigating the missing data mechanism in quality of life outcomes: a comparison of approaches [PDF]

, 2009
Background: Missing data is classified as missing completely at random (MCAR), missing at random (MAR) or missing not at random (MNAR). Knowing the mechanism is useful in identifying the most appropriate analysis. The first aim was to compare different
A Avenell, A Grant, Craig R Ramsay, D Curran, DB Rubin, DL Fairclough, DL Fairclough, DW Hosmer, G Molenberghs, J Listing, J Listing, JR Carpenter, MS Ridout, N Schmitz, Peter M Fayers, PJ Diggle, R Brooks, RJA Little, RJA Little, S Fielding, SH Ralston, Shona Fielding, The KAT trial group, The RECORD Trial Group   +23 more
core   +5 more sources

Problems in dealing with missing data and informative censoring in clinical trials

Current Controlled Trials in Cardiovascular Medicine, 2002
A common problem in clinical trials is the missing data that occurs when patients do not complete the study and drop out without further measurements. Missing data cause the usual statistical analysis of complete or all available data to be subject to ...
Shih Weichung
doaj   +1 more source

Evaluation of missing data mechanisms in two and three dimensional incomplete tables

, 2018
The analysis of incomplete contingency tables is a practical and an interesting problem. In this paper, we provide characterizations for the various missing mechanisms of a variable in terms of response and non-response odds for two and three dimensional
Ghosh, S., Vellaisamy, P.
core   +1 more source