Definition

In statistics, bias refers to the systematic error or deviation of a statistical estimate or measurement from the true or population value. When a measurement or an estimator is biased, it consistently overestimates or underestimates the true value in the same direction across multiple samples or observations. Bias can result from various sources, such as the sampling method, measurement instruments, or the choice of statistical model. It is a critical consideration because biased estimates can lead to inaccurate and misleading conclusions in data analysis. Statisticians often aim to reduce or eliminate bias in their analyses to obtain more accurate and reliable results.