Human Error
- Error that results from 'any action or lack there of that leads to exceeding the tolerances of the conditions required for the normal functioning of the measuring system with which the human interacts' Types of human error include:
- Action errors:
- Slips – a frequently performed action is done wrong or is carried out on the wrong object
- Lapses – a step is forgotten
- Thinking errors:
- Rule-based mistakes – a good rule/method is applied in the wrong way or a bad rule is followed (when rules/procedures are available)
- Knowledge-based mistakes – applying incorrect logic, resources, or lacking experience in a situation where no rules are available
- Action errors:
Systematic Error
- Error that is predictable and are secondary to the shortcomings of the measurement system itself
- Types of systematic error include:
- Environmental errors - the surroundings cause problems with the measurement system
- Instrumental errors - the measuring instrument itself is flawed and causes consistent inaccuracies
- Theoretical errors - the measurement procedure is flawed creating inaccuracies
Random Error
- Error that is uncontrollable and unpredictable and follows a Gaussian normal distribution - can be subjected to statistical analysis to reduce error