Top coding of extreme values of variables like income is a common method of statistical disclosure control, but it creates problems for the data analyst. The paper proposes two alternative methods to top coding for statistical disclosure control that are based on multiple imputation. We show in simulation studies that the multiple-imputation methods provide better inferences of the publicly rel...

Imputation using a regression model is a method to preserve the correlation among variables and to provide imputed point estimators. We discuss the implementation of regression imputation using fractional imputation. By a suitable choice of fractional weights, the fractional regression imputation can take the form of hot deck fractional imputation, thus no artificial values are constructed afte...

One of the most difficult problems confronting investigators who analyze data from surveys is how to treat missing data. Many statistical procedures cannot be used immediately if any values are missing. Imputation of missing data before starting statistical analysis is then necessary. This paper proposes imputation methods of the mean based on indirect estimators of available cases. A complete ...

Missing data are often a problem in social science data. Imputation methods fill in the missing responses and lead, under certain conditions, to valid inference. This article reviews several imputation methods used in the social sciences and discusses advantages and disadvantages of these methods in practice. Simpler imputation methods as well as more advanced methods, such as fractional and mu...

The soil samples were collected from 170 sampling stations in an arid area in Shahrood and Damghan, characterized by prevalence of mining activity. The levels of Co, Pb, Ni, Cs, Cu, Mn, Sr, V, Zn, Cr, and Tl were recorded in each sampling location. A new method known as min/max autocorrelation factor (MAF) was applied for the first time in the environmental research works to de-correlate these ...

Highway safety evaluation is one of the critical processes for identifying transportation system performance. The capabilities of common used safety assessing methodologies such as naïve before-after comparisons, safety audit, and statistical modelling, etc, are limited due to historical data availability, observation periods, or observer’ experience, and so on. Other than these traditional met...

During recent years the imputation strategy in Statistics Finland has been concretised so that we can speak about an integrated modelling approach (IMAI) to this kind of datacleaning (see Laaksonen 2000&2002a&2003, Chambers et al 2001, Piela and Laaksonen 2001). The strategy has been under consideration and consequently further developed in the two big European Union research projects, that is,...