In epidemiology,<unk> refers to bias arising from measurement error.<unk> is also referred to as observational bias and misclassification. A Dictionary of Epidemiology, sponsored by the International Epidemiological Association, defines this as the following: "1. A flaw in measuring exposure, covariate, or outcome variables that results in different quality (accuracy) of<unk>  between comparison groups. The occurrence of<unk> s may not be independent of the occurrence of selection biases. 2. Bias in an estimate arising from measurement errors."
Information bias 
Publication bias
Funding bias
Recall bias
Length time bias
Lead time bias
Age bias 
Restraint bias