Proficiency Testing
Definition
An external quality assurance programme in which a laboratory analyses blind samples distributed by an independent provider and submits results for comparison against known values or peer responses. Results identify systematic errors that internal controls may not detect. Participation is mandatory for accredited forensic laboratories in most jurisdictions.
- Required for
- ISO 17025 and ILAC-G19 accreditation
- Format
- Blind or semi-blind analysis of samples with known composition
- Key comparison
- Results measured against reference values and inter-lab performance
- Primary purpose
- Detect systematic errors by method or analyst
Common questions
What exactly is proficiency testing in forensics?+
Proficiency testing is when a lab analyzes samples of known composition without knowing the correct answers in advance. The results are then compared to reference values and to other participating labs. It's designed to reveal accuracy, error rates, and training gaps.
Why do forensic labs need to do proficiency testing?+
It's a mandatory requirement for ISO 17025 accreditation and the primary mechanism for detecting systematic errors by either the method or the analyst. It's also an independent check that catches problems the training organization might miss.
What do forensic examiners learn from proficiency testing results?+
Results measure accuracy and agreement with reference standards. They identify where individual examiners or methods are weak, reveal error rates, and help labs target training needs. In some fields like entomology, it also tests skills like specimen identification and PMI calculation.
Related terms
- ISO/IEC 17025
- The international standard for testing and calibration laboratories, published jointly by the International Organization for Standardization and the International Electrotechnical Commission. It...
- Chain of Custody
- The documented chronological record of who collected, handled, transferred, and examined a piece of evidence. For digital evidence, chain of custody includes...
- ISO 17025
- International standard for the general requirements for the competence of testing and calibration laboratories. Covers management system requirements (document control, internal audits,...
- Method Validation
- The process of demonstrating that an analytical method does what it claims: that it correctly identifies the target analyte, at what sensitivity,...
- Validation
- The process of establishing through systematic testing that a method does what it claims to do, within defined conditions and with a...
- Accreditation
- Formal recognition by a standards body (such as UKAS in the UK, A2LA in the US, or NABL in India) that a...
- Accreditation Body
- A national or regional organisation that assesses laboratories against ISO/IEC 17025 and grants accreditation. Examples include UKAS (United Kingdom Accreditation Service), NIST-associated...
- Blind Verification
- The procedure in which a second fingerprint examiner independently performs the Analysis and Comparison stages without knowledge of the first examiner's conclusion....
- Confirmation Bias
- The cognitive tendency to search for, interpret, favour, and recall information in a way that confirms or supports one's prior beliefs or...
- Contextual Bias
- The influence of case-relevant background information (suspect financial difficulties, police intelligence) on the direction of an examiner's technical analysis. Demonstrated experimentally for...
- Daubert Standard
- The US federal evidentiary standard (Daubert v. Merrell Dow Pharmaceuticals, 1993) requiring that expert testimony be based on scientifically valid methods with...
- EAFE
- The European Association for Forensic Entomology, founded in 2000. Publishes guidelines, holds annual scientific meetings, and has been the primary driver of...
Explained in these topics
- Accreditation and Quality as a Legal RequirementA quality assurance mechanism in which a laboratory analyses blind samples with known characteristics, and its results are compared against those from other la...
- Accreditation and Quality Systems in Wildlife ForensicsExternal quality assessment in which a laboratory analyses blind samples of known composition and its results are compared against the correct answer. Required...
- Cognitive Bias, Error and Quality in OdontologyExercises in which examiners compare against test samples with known answers to measure accuracy and agreement. Results reveal error rates and identify trainin...
- Forensic Biology Laboratory Organisation and AccreditationAn external quality assurance programme in which a laboratory analyses blind samples distributed by an independent provider and submits results for comparison...
- Standards, Error Rates and Quality in Forensic EntomologyBlind exercises in which participants analyse an unknown sample and their results are compared against a reference value. In forensic entomology these typicall...
- Quality Systems: ISO 17025 and AccreditationExternal performance assessment in which a lab analyses samples of known composition provided by a scheme operator, without knowing the correct answers in adva...
- Spectrographic Voiceprint History and Its Modern RejectionBlind or semi-blind testing of an examiner's conclusions against known ground truth by a body independent of the training organisation. Required under ISO 1702...