Regression estimation is a technique used to replace missing values in data

Data

The term data refers to qualitative or quantitative attributes of a variable or set of variables. Data are typically the results of measurements and can be the basis of graphs, images, or observations of a set of variables. Data are often viewed as the lowest level of abstraction from which...

. The variable with missing data is treated as the dependent variable, while the rest of the cases are treated as independent variables. A regression equation is then generated which can be used to predict missing values. This method reduces the variance associated with other techniques.
To better understand what regression estimation is, one must become familiar with the process of finding the regression estimation.

The first steps for finding regression estimations are to collect bivariate data

Bivariate data

In mathematics, bivariate data is data that involves two variables. The quantities from these two variables are often represented using a scatter plot...

 and plot it on a scatter plot.