Estimating Components of Mean Square Error for Mixed Mode Data Collection

Evidence-based management and development planning relies on official statistics. There are some obstacles that make it impossible to do single mode survey. These obstacles are sampling frame, time, the budget and accuracy of measurment of each mode. Always we can not use single mode survey becase of these factors. So we need to use other data collection method to overcome these obstacles. This method is called the mixed mode survey, which is a combination of several modes. In this article we show that mixed mode surveys can produce more accurate official statistics than single mode surveys.