When original participants in a longitudinal study drop out midway, it is called 

The correct answer is  Mortality

 Important Points

•  Longitudinal study
  • The research design involves repeated observations of the same variables over short or long periods. It is often an observational study, although it can also be structured as a longitudinal randomized experiment.
  • For example, a study was conducted to understand the similarities or differences between identical twins who are brought up together versus identical twins who are not. The study observes several variables, but the constant is that all the participants have identical twins.
  • Mortality selection occurs when a non-random subset of a population of interest has died before data collection and is unobserved in the data.
  • Mortality selection (i.e., selective survival) affects the definition of the population and the sample under study.

​ Additional Information

• Response bias
  • ​The deviation of the survey estimate from the true population value is due to measurement error from the data collection.
• A longitudinal redundancy check (LRC)
  • It is an error-detection method for determining the correctness of transmitted and stored data. LRC verifies the accuracy of stored and transmitted data using parity bits. It is a redundancy check applied to a parallel group of bit streams.