OSAC 2022-S-0012 Standard for Proficiency

Testing in Friction Ridge Examination 

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OSAC 2022-S-0012

Standard for Proficiency 

Testing in Friction Ridge 

Examination 

Friction Ridge Subcommittee

Physics/Pattern Scientific Area Committee

Organization of Scientific Area Committees (OSAC) for Forensic Science
OSAC 2022-S-0012 Standard for Proficiency

Testing in Friction Ridge Examination 

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OSAC 2022-S-0012

Standard for Proficiency Testing in 

Friction Ridge Examination

Prepared by 

Friction Ridge Subcommittee

Version: 2.0

April 2022

Disclaimer:

This OSAC Proposed Standard was written by the Organization of Scientific Area Committees (OSAC) 

for Forensic Science following a process that includes an open comment period. This Proposed Standard 

will be submitted to a standards developing organization and is subject to change.

There may be references in an OSAC Proposed Standard to other publications under development by 

OSAC. The information in the Proposed Standard, and underlying concepts and methodologies, may be 

used by the forensic-science community before the completion of such companion publications.

Any identification of commercial equipment, instruments, or materials in the Proposed Standard is not a 

recommendation or endorsement by the U.S. Government and does not imply that the equipment, 

instruments, or materials are necessarily the best available for the purpose.

To be placed on the OSAC Registry, certain types of standards first must be reviewed by a Scientific and 

Technical Review Panel (STRP). The STRP process is vital to OSAC’s mission of generating and 

recognizing scientifically sound standards for producing and interpreting forensic science results. The 

STRP shall provide critical and knowledgeable reviews of draft standards or of proposed revisions of 

standards previously published by standards developing organizations (SDOs) to ensure that the 

published methods that practitioners employ are scientifically valid, and the resulting claims are 

trustworthy.

The STRP panel will consist of an independent and diverse panel, including subject matter experts, 

human factors scientists, quality assurance personnel, and legal experts, which will be tasked with 

evaluating the proposed standard based on a comprehensive list of science-based criteria.

For more information about this important process, please visit our website 

at: https://www.nist.gov/topics/organization-scientific-area-committees-forensic-science/scientifictechnical-review-panels. 
OSAC 2022-S-0012 Standard for Proficiency

Testing in Friction Ridge Examination 

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Table of Contents

2. Scope ................................................................................................................................. 5

3. Terms and Definitions..................................................................................................... 5

4. General Requirements .................................................................................................... 7

4.1. Test Selection .............................................................................................................. 7

4.2. Test Development........................................................................................................ 7

4.3. Test Validation ............................................................................................................ 9

4.4. Test Administration................................................................................................... 10

4.5. Evaluation of Performance........................................................................................ 11

4.6. Documentation of Records........................................................................................ 12

5. Appendix A: Change Log.............................................................................................. 13
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Testing in Friction Ridge Examination 

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Introduction

1.1. This document has been developed with the objective of improving the quality and 

consistency of friction ridge examination practices.

1.2. The purpose of this document is to provide a standard for assessing the performance of 

individual Forensic Service Provider (FSP) personnel and the overall FSP quality system 

through proficiency testing in friction ridge examination. This document is intended to 

supplement the International Organization for Standardization / International 

Electrotechnical Commission (ISO/IEC) 17043 Conformity Assessment – General 

Requirements for Proficiency Testing standards with discipline-specific information for 

friction ridge proficiency examinations.

1.3. Proficiency testing is an integral component of an FSP’s quality assurance program. 

Proficiency testing provides a means of:

1.3.1. Evaluating the skills and abilities of individual FSP personnel to perform specific 

examinations.

1.3.2. Evaluating the effectiveness of an FSP’s quality system (e.g. facility, equipment, 

procedures, training, and quality controls).

1.3.3. Identification of actual or potential non-conformities in the quality system.

1.3.4. Identification of interlaboratory differences.

1.4. Tests can vary in design, quality, and difficulty—and thus in predictive value. The 

reliability of results produced by an FSP depend on:

1.4.1. The performance of the FSP when tested, and

1.4.2. The robustness of the test upon which performance was assessed.

1.5. The robustness of the test depends on factors related to the development, validation, and 

administration of the test as well as the evaluation of the results.

1.6. Conformance to this Standard ensures that FSPs select tests for which the necessary 

documentation is available to enable a third-party evaluation of the robustness of the 

test. Conformance to this Standard alone, without consideration of the robustness of the 

test upon which performance was assessed, does not imply the performance of the FSP is 

reliable or satisfactory. 

1.7. In this document, the following verbal forms are used: “shall” indicates a requirement, 

“should” indicates a recommendation; “may” indicates permission; and “can” indicates a 

possibility or capability. 
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2. Scope

2.1. This document prescribes the minimum requirements for the selection, development, 

validation, administration, evaluation, and documentation of proficiency tests used by 

Forensic Service Providers (FSPs) for purposes of assessing the performance of the FSP 

personnel and overall FSP quality system related to friction ridge examination. These 

requirements are applicable to tests generated internally by FSPs and tests obtained from 

external sources.

2.2. This document does not address requirements related to:

2.2.1. The specific method(s) for conducting friction ridge examinations.

2.2.2. Validation of novel methods prior to implementation.

3. Terms and Definitions

For the purposes of this document, the following terms and definitions apply.

3.1. Acceptable Result: A result that conforms to the assigned value, or is otherwise 

permissible under casework conditions by FSP policy.

3.2. Assigned Value: Value attributed to a particular property of a proficiency test item. 

NOTE: The assigned value provides the basis for which participant results are expected 

to conform and performance is evaluated.

3.3. Complexity (of a Comparison): A characteristic of a comparison in which the attributes 

of one or both impressions may require additional consideration and quality control 

measures as it relates to the evaluation of a source conclusion. Comparisons can be 

designated as high complexity, low complexity, or non-complex.

3.4. Complexity (of an Impression): A characteristic of an impression whose attributes may 

require additional consideration and quality control measures. Impressions can be 

designated as high complexity, low complexity, or non-complex.

3.5. Consultation: A significant interaction, prior to the initiation of verification or technical 

review process, between qualified FSP personnel regarding one or more impressions in 

question. NOTE: An interaction is considered “significant” when it involves a partial 

or complete examination of the impression(s) in question. 

3.6. Corrective Action: An action to eliminate the cause of a non-conformity and to prevent 

recurrence. 

3.7. Examination: The act or process of observing, searching, detecting, recording, 

prioritizing, collecting, analyzing, measuring, comparing, and/or interpreting.
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3.8. Forensic Service Provider (FSP): A forensic science entity or forensic science 

practitioner providing forensic science services.

3.9. Friction Ridge Detail/Features: The combination of ridge flow, ridge characteristics, 

and ridge structure of friction ridge skin, as observed and reproduced in an impression. 

A large subset of the observed data used to compare and interpret similarity or 

dissimilarity between two impressions. 

3.10. Ground Truth: The actual or true state of affairs concerning the source or type of items 

submitted for evaluation.

3.11. Interlaboratory Comparison: Organization, performance and evaluation of 

measurements or tests on the same or similar items by two or more FSPs in accordance 

with predetermined conditions.

3.12. Intralaboratory Comparison: Organization, performance and evaluation of 

measurements or tests on the same or similar items within the same FSP in accordance 

with predetermined conditions.

3.13. Nonconformity: Non-fulfillment of a requirement.

3.14. Observed Data: Any demonstrable information observed within an impression that an 

examiner relies upon to reach a decision, conclusion, or opinion. This has historically 

been expressed as “features” or “minutiae,” but the use of the broader term “observed 

data” is inclusive of other types of data that may be considered beyond minutiae, such 

as quality, scars, creases, edge shapes, pore structure, and other friction ridge features. 

3.15. Participant: Laboratory, organization or individual that receives proficiency test items 

and submits results for review by the proficiency test provider.

3.16. Proficiency Testing: Evaluation of participant performance against pre-established 

criteria by means of interlaboratory comparisons. 

3.17. Technical Review: A qualified second party’s evaluation of reports, notes, data, and 

other documentation to ensure there is appropriate and sufficient support for the 

actions, results, conclusions, opinions, and interpretations. 

3.18. Test Sample: A subset of items included as part of a test which are subject to 

examination by FSP personnel.

3.19. Test Specimen: A single item of the test sample.

3.20. Verification: Confirmation, through either re-examination or review of documented 

data by another examiner, that a conclusion or opinion conforms to specified 

requirements and is reproducible. NOTE: “Specified requirements” are the FSP’s 
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Testing in Friction Ridge Examination 

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policies and procedures relating to Analysis, Comparison and Evaluation of friction 

ridge impressions.

4. General Requirements

4.1. Test Selection

4.1.1. Tests shall be selected which have been developed and validated in accordance 

with the requirements set forth in this Standard (Sections 4.2 and 4.3).

4.1.2. Where available and appropriate for the job function(s) being tested, tests shall be 

obtained from an external source through participation in a proficiency testing 

program offered by a provider accredited to the ISO/IEC 17043 international 

standard. 

4.1.3. Where not available or not appropriate for the specific job function(s) being 

tested, tests may be obtained from an external source through participation in an 

interlaboratory comparison or developed internally by the FSP through 

participation in an interlaboratory comparison or intralaboratory comparison.

4.2. Test Development

4.2.1. Tests shall be developed to assess the performance of the FSP as it relates to all 

major job functions performed by the FSP. These areas may include but are not 

limited to the following:

4.2.1.1. Detection of friction ridge impressions through optical, physical, and 

chemical processing / development techniques.

4.2.1.2. Preservation of friction ridge impressions through photography and/or 

digital capture.

4.2.1.3. Enhancement of friction ridge impressions through digital processing.

4.2.1.4. Recording exemplar impressions.

4.2.1.5. Examination (Analysis, Comparison, and Evaluation) of friction ridge 

impressions, including scenarios involving:

4.2.1.5.1. Potential donor sources selected arbitrarily.

4.2.1.5.2. Potential donor sources selected as a result of their similarity to 

one another, such as being derived from the result of an Automated 

Biometric Identification System (ABIS) search of the unknown 

impression.
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4.2.1.6. Encoding, searching, and retrieving friction ridge impressions using ABIS.

4.2.2. The extent to which a test sample is representative of casework shall be 

documented as it relates to the types, qualities, and conditions of the test 

specimens for the job functions being tested. Methods used to measure and assess 

the representativeness of the test sample to casework shall be documented and can 

range from subjective assessment by expert(s) to more objective approaches such 

as expert consensus panels or automated software. Statistical analyses 

appropriate for the type of data generated from the measurements should be used 

to demonstrate the extent to which the test sample compares to casework. 

NOTE 1: The OSAC Friction Ridge Subcommittee Proposed Best Practice 

Recommendations for Analysis and Comparison & Evaluation provide 

recommendations related to categorizing the quality of friction ridge 

detail/features, complexity (of an Impression), and complexity (of a Comparison) 

through observation.

NOTE 2: Objective methods, such as automated software (where appropriate) or 

expert consensus panels, are more robust than subjective methods for assessing 

representativeness of test samples to casework.

4.2.3. Test samples should include a variety of different substrate types (e.g., porous, 

non-porous, semi-porous, curved, pliable), friction ridge development techniques 

(e.g., optical, chemical, and physical processes), and deposition matrices (e.g. 

sweat, oils, blood, livescan, ink).

4.2.4. Tests shall include response choices which allow for the full range of association 

and non-association source conclusions that can be encountered in casework. At 

a minimum, tests shall include response choices which include source conclusions 

representing the strongest support for same sources (e.g., source identification), 

the strongest support for different sources (e.g., source exclusion), and insufficient 

support for a stronger source conclusion (e.g., inconclusive).

NOTE: The OSAC Friction Ridge Subcommittee Proposed Standard for Friction 

Ridge Examination Conclusions provides qualitative expressions for the range of 

conclusions that may be reached following friction ridge comparisons.

4.2.5. Test samples should only include impressions for which the ground truth state is 

known.

NOTE: Knowledge of ground truth is more robust and enables performance to be 

measured in terms of both accuracy and consistency. Ground truth is essential for 

measuring accuracy; however, ground truth is not necessary for measuring 

consistency between participants through participation in proficiency testing 

programs or other interlaboratory comparisons or intralaboratory comparisons. In 
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circumstances where it is impractical to create suitable test specimens for which 

ground truth is known, casework samples can be used to assess performance in 

terms of consistency and agreement with assigned values. 

4.2.6. Test specimens shall each have an assigned value for which participant results are 

expected to conform and performance is evaluated. Criteria for determining the 

assigned values shall be documented, appropriate for the performance 

characteristic being measured (e.g., accuracy and/or consistency), and based on 

observable or measurable attributes of the test specimens (e.g., quality and 

quantity of friction ridge detail/features). Where applicable to the job function 

being tested (e.g., examination of friction ridge impressions), the observable or 

measurable attributes of the test specimen to support a source conclusion should 

conform to those criteria established by a national standard or consensus body 

recognized by the OSAC.

NOTE: Knowledge of ground truth for test specimens is not always sufficient for 

determining the assigned value. For tests designed to assess performance related 

to examination of friction ridge impressions, test specimens might be known to 

have come from same (or different) sources but lack sufficient observable or 

measurable attributes to support a strong source conclusion (e.g., source 

identification or source exclusion). In these circumstances, a response choice 

indicating insufficient support for a stronger source conclusion (e.g., 

inconclusive) can be the assigned value.

4.2.7. Neither the ground truth nor assigned values for test specimens shall be disclosed 

to the participants to which the test is administered until after the test is 

completed. 

4.3. Test Validation

4.3.1. Tests shall be validated prior to administration to participants.

4.3.1.1. Tests obtained from external sources should include a description of how 

the tests were developed and validated in accordance with the 

requirements specified in Sections 4.2 and 4.3 of this Standard, to allow 

the FSP to verify conformance to this Standard and serve as evidence of 

conformity. Documentation of the validation completed by the external 

provider can serve as evidence of conformity. 

4.3.1.2. Tests developed by the FSP or tests obtained from external sources that do 

not include a description of how the tests were developed and validated in 

accordance with the requirements specified in Sections 4.2 and 4.3 of this 

Standard shall be validated by the FSP to verify conformance to this 

Standard. Documentation of the validation completed by the FSP can 

serve as evidence of conformity.
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4.3.2. Test validation shall include the following:

4.3.2.1. Ensuring that test samples are representative of those encountered in 

casework as it relates to the types, qualities, and conditions of the test 

specimens for the job functions being tested.

4.3.2.2. Verification that the test can be completed using the materials included in 

the test by pre-distribution administration of the test to participants 

independent of the test development and in the same conditions as the 

proposed test.

NOTE: For tests developed or validated by the FSP, the personnel 

participating in the pre-distribution administration of the test can be 

internal or external to the FSP. 

4.3.2.3. Verification that the pre-distribution test results correspond to the assigned 

values.

4.3.3. The results of the validation—with sufficient detail to demonstrate that the test 

conforms to the requirements set forth by this Standard—shall be documented and 

maintained by the FSP.

4.4. Test Administration

4.4.1. The FSP shall be responsible for ensuring the test has been validated prior to 

distribution. Documentation verifying the test has been developed and validated 

in accordance with the requirements specified in Sections 4.2 and 4.3 of this 

Standard shall be obtained or produced by the FSP prior to test administration. 

This applies to tests developed internally or obtained from external sources.

4.4.2. All FSP personnel shall participate in at least one proficiency testing program, 

interlaboratory comparison, or intralaboratory comparison annually. 

4.4.3. Tests shall only be administered to FSP personnel approved to perform 

independent casework.

4.4.4. Tests shall be administered in conditions reflecting casework (e.g., environmental 

conditions, equipment, time constraints) and in accordance with applicable FSP 

policies and procedures. 

4.4.5. Tests shall be administered such that the results produced by individual FSP 

personnel are their own and not influenced by other participants, such as through 

Consultation, prior to Verification or Technical Review.
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NOTE: This does not preclude participants from using tools or equipment 

(including automated comparison software or statistical models) that are 

otherwise available and permissible for use in normal casework.

4.4.6. Tests should be administered such that participants are not exposed to cues—no 

matter how subtle—that may hint at or guide them to the expected results without 

direct examination of the test specimen.

NOTE: Subtle cues can be unintentionally introduced or inferred by the design or 

administration of a single test or patterns that emerge from a sequence of tests 

(see e.g., OSAC Technical Series 004: Human Factors in Validation and 

Performance Testing of Forensic Science --

https://doi.org/10.29325/OSAC.TS.0004).

4.4.7. Tests may be administered in one of two formats:

4.4.7.1. Non-blind testing: Participants are aware they are being tested.

4.4.7.2. Blind testing: Participants are not aware they are being tested.

NOTE: Blind testing is more robust than non-blind testing.

4.5. Evaluation of Performance

4.5.1. The FSP shall have established criteria for evaluating acceptable performance as 

it relates to both the individual FSP personnel and overall FSP quality system. 

Methods used to evaluate performance shall be documented and include statistical 

analyses appropriate for the evaluation. These criteria and methods shall be 

documented prior to test administration and address:

4.5.1.1. Agreement of participant results to the assigned values.

4.5.1.2. Sufficient documentation of observed data to support the participant’s 

results.

4.5.1.3. Completion of the test in accordance with applicable FSP policies and 

procedures.

NOTE 1: Acceptable performance can allow for deviations from the 

assigned values provided the extent of allowable deviations are 

documented prior to test administration and bounded within the range of 

acceptable results that are normally permissible under casework 

conditions. 

NOTE 2: Performance of individual FSP personnel is evaluated based on 

the results produced prior to the application of quality controls involving 
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influence by other participants, such as Verification or Technical Review. 

Performance of the overall FSP quality system is evaluated based on the 

results produced after the application of quality controls involving 

influence by other participants, such as Verification or Technical Review.

4.5.2. Cause analysis shall be performed when a result is generated during the test that 

does not correspond to the assigned value or exceeds the range of acceptable 

results. Corrective actions shall be taken where appropriate.

NOTE: Cause analysis can include consideration of factors related to the 

environment, facilities, equipment, examination method, policies and procedures, 

training, and skills or abilities of the FSP personnel.

4.6. Documentation of Records

4.6.1. The FSP shall have a procedure to maintain records documenting the following as 

it relates to the selection, development, validation, and administration of the test, 

as well as evaluation of the results in accordance with the requirements and 

recommendations set forth in Sections 4.2 through 4.5 of this Standard:

4.6.1.1. The identity of the Proficiency Testing Program Manager responsible for 

the selection, administration, and evaluation of tests within the FSP.

NOTE: The proficiency testing program manager can be a Quality 

Assurance Manager, Supervisor, or otherwise designated FSP personnel.

4.6.1.2. The source of the test (for tests obtained from external sources) or identity 

of the personnel responsible for developing the test along with their 

qualifications (for tests developed internally).

4.6.1.3. The job function(s) tested.

4.6.1.4. Assurance that the test has been developed and validated in accordance 

with the requirements set forth in Sections 4.2 and 4.3 of this Standard. 

4.6.1.5. A description of the types of substrates included in the development of the 

test.

4.6.1.6. A description of the development techniques included in the development 

of the test.

4.6.1.7. A description of the deposition matrices of the test samples included in the 

development of the test.

4.6.1.8. A description of the scenario(s) presented in the test, including any 

supplemental background or contextual information.
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4.6.1.9. Criteria for determining the assigned values for each test specimen.

4.6.1.10. Assurance that the personnel participating in the pre-distribution 

administration of the test is qualified to validate the job function evaluated 

by the test.

4.6.1.11. A list of the FSP personnel to which the test was administered.

4.6.1.12. The date the test was administered to participant(s) and the date the test 

was completed by the participant(s).

4.6.1.13. Conditions under which the test was administered to the participants.

4.6.1.14. Format of the test administered to the participants (non-blind or blind).

4.6.1.15. Participant responses.

4.6.1.16. Criteria for acceptable performance as it relates to:

4.6.1.16.1. Individual FSP personnel.

4.6.1.16.2. Overall FSP quality system.

4.6.1.17. Results of participant performance as it relates to:

4.6.1.17.1. Individual FSP personnel.

4.6.1.17.2. Overall FSP quality system.

4.6.1.18. Cause analysis and applicable corrective action(s).

4.6.2. Documentation shall be sufficient to enable a third party to interpret and evaluate 

the robustness of the development, validation, administration, and evaluation of 

the test used to assess the performance of the FSP personnel and quality system 

overall. 

5. Appendix A: Change Log

Version Date Change

1.0 10/4/2021 Original Issue

2.0 4/20/2022 Final Issue