Systematic Error

Systematic error is any error that has a consistent effect. Systematic error results from consistent but inaccurate responses. Using the example of a weighing machine, readings that are consistently off in one direction reflect systematic error, although additional nuances will be subsequently discussed. The causes of systematic error could include leading or biased questions, which are often aspects of the measurement process that typically cause respondents to be unwilling to provide an accurate response. Being unwilling to provide an accurate response, respondents might provide a response that is inaccurate yet consistent. For example, with a leading question, respondents might consistently provide a response that is more acceptable. With a question requiring estimation of the amount of beer consumed, respondents might systematically underestimate the true value ...