What is meant by MAR?

MAR stands for "Missing At Random," a term used in statistics and data analysis to describe a specific type of missing data mechanism. In this context, the likelihood of a data point being missing is related to observed data but not to the value of the missing data itself. This assumption allows researchers to use certain statistical methods to handle missing data without introducing significant bias. It contrasts with other types of missing data mechanisms, such as "Missing Completely At Random" (MCAR) and "Missing Not At Random" (MNAR).