A rather loosely defined expression which in general means, or ought to mean, a bias which is due to the nature of the situation and cannot, for example, be removed by increasing the sample size or choosing a different type of estimator. An example of inherent bias is the systematic error of an observer or an instrument; a further example, in the interrogation of human population, is the distortion of truth by the respondent for reasons of prestige, vanity or sympathy with the investigator.