OSAC Lexicon
The OSAC Lexicon is a compendium of forensic science terms and definitions. This terminology tool was created to help bring consistency and understanding to the way terms are used by the various forensic science. Use of the OSAC Lexicon does not replace the need to reference the original published source.
The terms and definitions in the OSAC Lexicon come from the published literature, including documentary standards and technical reports. It is continually updated with the latest work from OSAC units, as well as terms from newly published documentary standards and standards elevated to the OSAC Registry.
Gradually terms are evaluated and harmonized by the OSAC to a single term. This process results in an OSAC Preferred Term. An OSAC Preferred Term is a term, along with its definition, that has undergone review and evaluation by the FSSB Terminology Task Group and has been approved by the FSSB. The FSSB recommends that subcommittees use OSAC Preferred Terms when drafting standards.
The OSAC Lexicon should be the primary resource for terminology and used when drafting and editing forensic science standards and other OSAC work products.
colors produced by the interference of two out-of-phase rays of white light when a birefringent material is observed at a non-extinction position between crossed polars.
Colors produced by the interference of two out-of-phase rays of white light when a birefringent material is observed at a non-extinction position between crossed polars
the pattern that results from constructive and destructive interference of light waves.
The pattern that results from constructive and destructive interference of light waves
Experiments performed to determine substances that inhibit or affect the intensity of the assay signal.
Non-targeted substances (i.e., matrix components, other drugs and metabolites, internal standard, impurities) which may impact the ability to detect, identify, or quantitate a targeted analyte.
Non-targeted analytes (i.e., matrix components, other drugs and metabolites, internal standard, impurities) which may impact the ability to detect, identify, or quantitate a targeted analyte
chemical found in a sample that interferes with identification of the analyte(s) of interest; this can include pyrolysis products, combustion products, and substrate background products.
Organization, performance and evaluation of measurements or tests on the same or similar items by two or more laboratories in accordance with predetermined conditions. (Source: ISO/IEC 17043:2010, 3.4)
Organization, performance and evaluation of measurements or tests on the same or similar items by two or more laboratories in accordance with predetermined conditions.
Also referenced in ANSI/ASTM E3255-21 Standard Practice for Quality Assurance of Forensic Science Service Providers Performing Forensic Chemical Analysis.
A raster scan technique in which the electron beam alternately refreshes all even, then all odd, scan lines of a display surface.
A raster scan technique in which the electron beam alternately refreshes all even, then all odd, scan lines of a display surface
A person who takes part in a dialog (Oxford English Dictionary Thumb Edition, 10thEdition, 2002). In Record Type-11, an interlocutor is any speaker in the recording whois not the subject of the ANSI/NIST-ITL transaction. An interlocutor may be the subjectof the record, within the transaction, however.
Substance that is manufactured for and consumed in or used for chemical processing to be transformed into another substance.
Substance that is manufactured for and consumed in or used for chemical processing to be transformed into another substance
Any media or device on which data is temporarily stored for transfer to permanent or archival storage.
Any media or device on which data is temporarily stored for transfer to permanent or archival storage
An evaluation of practitioner performance against pre-established criteria by means of intralaboratory comparisons.
The accumulation of test data within the laboratory to demonstrate that established parameters, software settings, formulae, algorithms and mathematical functions perform as expected; and that the information/results/data obtained is correct and consistent with expected values.
The accumulation of test data within the laboratory for developing the laboratory standard operating procedures and determining the limits of the method(s). Internal validation demonstrates that the established protocols for the technical steps of the test and for data interpretation perform as expected in the laboratory.
1) In general, the accumulation of test data within the laboratory for developing the laboratory standard operating procedures and demonstrating that the established protocols for the technical steps of the test and for data interpretation perform as expected in the laboratory. 2) In the context of probabilistic genotyping, the accumulation of test data within the laboratory to demonstrate that established parameters, software settings, formulae, algorithms and mathematical functions perform as expected; and that the information/results/data obtained is correct and consistent with expected values.
The accumulation of test data within the laboratory for developing the laboratory standard operating procedures and determining the limits of the method(s). Internal validation demonstrates that the established protocols for the technical steps of the test and for data interpretation perform as expected in the laboratory.
The accumulation and evaluation of test data within the laboratory for developing the laboratory standard operating procedures and demonstrating that the established protocols for the technical steps of the test and for data interpretation perform as expected in the laboratory. The parameters (e.g., any variable that impacts interpretation) included in a test protocol used by the laboratory should be supported by validation studies conducted with samples of known origin similar to the types of samples routinely accepted and tested by the laboratory
The acquisition of test data within the laboratory to verify the functionality of the system, the accuracy of statistical parameters, the appropriateness of analytical and statistical parameters, and the determination of limitations of the system
An in-depth educational or training program that offers a period of supervised practical experience in a forensic science setting.
An in-depth educational or training program that offers a period of supervised practical experience in a forensic science setting
International Criminal Police Organization.
The estimation of the value of a sampled function at an arbitrary ordinal using the closest samples.
The estimation of the value of a sampled function at an arbitrary ordinal using the closest samples
A Category 1 scoring function. The score is explainable and has quantifiable meaning.
Explanations for the observations, data, and calculations.
Also referenced in ANSI/ASB 040 Standard for Forensic DNA Interpretation and Comparison Protocols, ANSI/ASB 038 Standard for Internal Validation of Forensic DNA Analysis Methods.
The process of evaluating DNA data for purposes including, but not limited to, defining assumptions related to mixtures and single source profiles, distinguishing between alleles and artifacts, assessing the possibility of degradation, inhibition, and stochastic effects, and determining whether the data are suitable for comparison.
Factual statements concerning detected analytes that may include, but not be limited to: drug scheduling information; pharmacokinetic/toxicokinetic information; pharmacodynamics/ toxicodynamic information; or information regarding factors that can affect detection or quantitation of the analyte
Occurring among different species.
In classical conditioning, the time elapsed between the conditioned stimulus and the unconditioned stimulus. In habituation, the time between exposures to a stimulus.
A schedule in which reinforcement is delivered on the basis of the amount of time before a response can be reinforced. The interval may be fixed or variable.
Organization, performance and evaluation of measurements or tests on the same or similar items within the same laboratory in accordance with predetermined conditions.
Also reference in ANSI/ASTM E3255-21 Standard Practice for Quality Assurance of Forensic Science Service Providers Performing Forensic Chemical Analysis
Organization, performance and evaluation of measurements or tests on the same or similar items within the same laboratory in accordance with predefined conditions. (Source: ISO 17025:2017, 3.4)
Occurring within the same species.
Software or hardware that are used to identify attacks or anomalies on computers or networks or both
For the purpose of Chapter 29, the terms site and scene will be jointly referred to as the investigation site, unless the particular context requires the use of one or the other word.
A group of individuals working on behalf of an interested party to conduct an investigation into the incident.
In MS, the ratio of the instrument responses between two previously identified diagnostic ions.
In MS, the ratio of the instrument responses between two previously identified diagnostic ions.
The physicochemical process of producing a gas-phase ion. In the mass spectrometer this typically occurs within the ion source. Several mechanisms of ionization exist such as chemical and electron ionization.
The physicochemical process of producing a gas-phase ion. In the mass spectrometer this typically occurs within the ion source. Several mechanisms of ionization exist such as chemical and electron ionization.
Direct or indirect alteration or interference in the instrument response due to the presence of co-eluting compounds
International Phonetic Alphabet
Iris Exchange Program. This is a program at NIST in support of iris-based applicationsbased on standardized interoperable iris imagery. See http://www.nist.gov/itl/iad/ig/irex.cfm
A thin, colored, approximately circular structure surrounding the pupil of the eye thatcontains features used for identification of individuals.