Two-Way Imputation
Two-way imputation using the simple method of Sijtsma and van der Ark (2003) and the MCMC based imputation of van Ginkel, van der Ark, Sijtsma and Vermunt (2007).
tw.imputation(data, integer=FALSE) tw.mcmc.imputation(data, iter=100, integer=FALSE)
data |
Matrix of item responses corresponding to a scale |
integer |
A logical indicating whether imputed values should be integers.
The default is |
iter |
Number of iterations |
For persons p and items i, the two-way imputation is conducted by posing a linear model of tau-equivalent measurements:
X_{pi}=θ_p + b_i + \varepsilon_{ij}
If the score X_{pi} is missing then it is imputed by
\hat{X}_{pi}=\tilde{X}_p + b_i
where \tilde{X}_p is the person mean of person p of the remaining items with observed responses.
The two-way imputation can also be seen as a scaling procedure to obtain a scale score which takes different item means into account.
A matrix with original and imputed values
Sijtsma, K., & Van der Ark, L. A. (2003). Investigation and treatment of missing item scores in test and questionnaire data. Multivariate Behavioral Research, 38(4), 505-528. doi: 10.1207/s15327906mbr3804_4
Van Ginkel, J. R., Van der Ark, A., Sijtsma, K., & Vermunt, J. K. (2007). Two-way imputation: A Bayesian method for estimating missing scores in tests and questionnaires, and an accurate approximation. Computational Statistics & Data Analysis, 51(8), 4013-4027. doi: 10.1016/j.csda.2006.12.022
The two-way imputation method is also implemented in
the TestDataImputation::Twoway
function of the
TestDataImputation package.
############################################################################# # EXAMPLE 1: Two-way imputation data.internet ############################################################################# data(data.internet) data <- data.internet #*** # Model 1: Two-way imputation method of Sijtsma and van der Ark (2003) set.seed(765) dat.imp <- miceadds::tw.imputation( data ) dat.imp[ 278:281,] ## IN9 IN10 IN11 IN12 ## 278 5 4.829006 5.00000 4.941611 ## 279 5 4.000000 4.78979 4.000000 ## 280 7 4.000000 7.00000 7.000000 ## 281 4 3.000000 5.00000 5.000000 ## Not run: #*** # Model 2: Two-way imputation method using MCMC dat.imp <- miceadds::tw.mcmc.imputation( data, iter=3) dat.imp[ 278:281,] ## IN9 IN10 IN11 IN12 ## 278 5 6.089222 5.000000 3.017244 ## 279 5 4.000000 5.063547 4.000000 ## 280 7 4.000000 7.000000 7.000000 ## 281 4 3.000000 5.000000 5.000000 ## End(Not run)
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