Question 2.8

Are missing values and the way they are imputed in PECBMS typical for bird monitoring?


No. Missing values are apparent in any survey data and in many statistical fields these need to be taken into account. E.g. in the field of economical statistics, the European Commission supports the development of a set of handbooks on the application of best international statistical principles, methods and practices by all producers of European Statistics in order to enhance their quality. Imputation, such as applied in PECBMS, is among the important methods in these handbooks, because “ignoring missing values can seriously affect the quality of data, potentially leading to biased conclusions and loss of precision” (quoted from ISTAT, CBS & SFSO, 2007).