What is a selection bias and a measurement bias?

Question

What is a selection bias and a measurement bias?

Answer 1

Selection bias is person making a choice for the team based on personal reasons. Or a system which doesn't evaluate all the important characteristics on an equal bases.

i.e. In making a car purchase, a person is biased toward a certain manufacturer, ignoring the pros and cons.

Measurement bias is the error in the metrology method. This could be man or instrument or other characteristcs contributing to the bias or error. i.e. When measuring the output power of an engine you compare the power of one car located in Denver, CO and another in SanDiego, CA. You don't consider the difference in altitude.