Module CC-03 · Version 1.0
Accuracy, Precision, Bias, and Measurement Uncertainty
A working method for describing why repeated results differ: separate imprecision (spread) from bias (closeness to a target), calculate mean, SD, and %CV, compare a result against an allowable-difference criterion, and state what a measurement uncertainty estimate does and does not claim.
Your next section
Start section 1Read without an account. Sign in to save.
Who this module is for
Clinical laboratory scientists and trainees who run quantitative chemistry testing and interpret QC and proficiency testing results.
Learning objectives
- Calculate and interpret mean, standard deviation, and coefficient of variation
- Differentiate random error, systematic error, bias, and total observed difference
- Explain measurement uncertainty in practical terms without treating it as a universal pass-fail number
How completion works
Mark every required section done and answer every knowledge check in those sections correctly. The final save completes the module automatically.
Sources
10 sources
1. Centers for Medicare & Medicaid Services. 42 CFR 493.1253, Standard: Establishment and verification of performance specifications. Electronic Code of Federal Regulations, current text as amended through 68 FR 50724 (Aug. 22, 2003).
Source note · federal regulation
2. Centers for Medicare & Medicaid Services. 42 CFR 493.1256, Standard: Control procedures. Electronic Code of Federal Regulations, current text.
Source note · federal regulation
3. Centers for Medicare & Medicaid Services. 42 CFR 493.931, Routine chemistry proficiency testing challenges and Table 2 acceptable performance criteria, current text per 87 FR 41238 (July 11, 2022).
Source note · federal regulation
4. Clinical and Laboratory Standards Institute. EP05, Evaluation of Precision of Quantitative Measurement Procedures, 4th edition (December 11, 2025).
Source note · consensus standard
5. Clinical and Laboratory Standards Institute. EP15, User Verification of Precision and Estimation of Bias (EP15-A3, reaffirmed September 2019).
Source note · consensus standard
6. Clinical and Laboratory Standards Institute. EP09, Measurement Procedure Comparison and Bias Estimation Using Patient Samples, 3rd edition (June 20, 2018).
Source note · consensus standard
7. Clinical and Laboratory Standards Institute. EP29-A, Expression of Measurement Uncertainty in Laboratory Medicine (January 2012).
Source note · consensus standard
8. Oosterhuis WP, Theodorsson E. Total error vs. measurement uncertainty: revolution or evolution? Clin Chem Lab Med. 2016;54(2):235-239.
Source note · peer-reviewed literature
9. Coskun A, Theodorsson E, Oosterhuis WP, Sandberg S; EFLM Task and Finish Group. Measurement uncertainty for practical use. Clin Chim Acta. 2022;531:352-360.
Source note · peer-reviewed literature
10. CLSI EP05 and CLSI EP15 (current editions), publisher description of mean, SD, and %CV as standard descriptive statistics for precision.
Source note · consensus standard