Authors: B. Baris Alkan; Nesrin Alkan; Cemal Atakan; Yuksel Terzi
Addresses: Faculty of Science and Arts, Department of Statistics, Sinop University, 57000 Sinop, Turkey ' Faculty of Science and Arts, Department of Statistics, Sinop University, 57000 Sinop, Turkey ' Faculty of Science, Department of Statistics, Ankara University, 06100 Ankara, Turkey ' Faculty of Science and Arts, Department of Statistics, Ondokuz Mayis University, 55139 Samsun, Turkey
Abstract: This study was performed to assess the effects of different imputation methods on the performance of a biplot technique. We selected the Fisher's iris data as our reference dataset. Some elements of the Iris data were deleted in different rates under missing at random (MAR) assumption to generate incomplete datasets which had 3.5%, 7%, 15%, 20% missing value. Datasets with missing values were completed by four imputation methods [mean imputation, regression imputation, expectation maximisation (EM) algorithm, multiple imputation (MI)]. The new imputed datasets were analysed by biplot technique and their results were compared with original complete biplot of the data. The results of biplot analysis were similar in all the imputation methods when missing rate is low under MAR assumption. Even when the missing rate was greater than 10%, results of EM and MI methods were similar to real values and graphical representation of original data. For multivariate methods, we also propose filling in the missing value with the arithmetic mean of the imputed estimates which are obtained with multiple imputation. This paper also indicates that the use of biplot technique for the comparison of the missing value imputation methods provides a useful visual tool.
Keywords: missing values; imputation methods; biplot analysis; incomplete datasets; mean imputation; regression imputation; expectation maximisation; multiple imputation; missing value imputation.
International Journal of Data Analysis Techniques and Strategies, 2015 Vol.7 No.3, pp.217 - 230
Available online: 21 Aug 2015 *Full-text access for editors Access for subscribers Purchase this article Comment on this article