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.
(1) (qualitative): the extent to which other substances interfere with the determination of a substance according to a given procedure, and (2) (quantitative): a term used in conjunction with another substantive (for example, constant, coefficient, index, factor, number) for the quantitative characterization of interferences.
the result of exothermic reactions, occurring spontaneously in some materials under certain conditions, whereby heat is generated at a rate sufficient to raise the temperature of the material.
Ignition resulting from self-heating, synonymous with spontaneous ignition.
The minimum temperature at which the self-heating properties of a material lead to ignition.
the woven edge portion of a fabric parallel to the warp.
Conformance to ensure that the biometric transaction is a faithful representation of theparent biometric data and thereby ensuring that the requirements are satisfied that are notmerely syntactic or morphological.
explosive compound that increases the sensitivity of the shock-sensitive component of a primer.
The partial derivatives of a measurement function that describe how the measurand's value varies with changes in the values of the input quantities.
Periods during early development when an animal is notably sensitive to stimuli that may create a specific association or otherwise alter their behavior and that remains relatively stable over time.
Studies performed to assess the ability of the probabilistic genotyping system to support the presence of a known contributor
A set of critical studies performed during developmental and/or internal validation of DNA or other test methods designed to define the lower and upper limits/ bounds of an assay to accurately detect an analyte.
Experiments performed to define the lower and upper limits/bounds of an assay to accurately detect an analyte. Experiments include a serial dilution performed during developmental and/or internal validation of methods.
The amount of stimuli that is necessary to produce a response from the canine.
A laboratory technique used to determine the sequence of bases (A, C, G, and T) in a DNA molecule.
The percentage or number of nucleotides or amino acids that are identical between two sequences.
Result of at least one activity necessarily performed at the interface between the supplier and the customer, which is generally intangible
result of at least one activity necessarily performed at the interface between the supplier and the customer,which is generally intangibleNOTE 1 Provision of a service can involve, for example, the following:- an activity performed on a customer-supplied tangible product (e.g. automobile to be repaired);- an activity performed on a customer-supplied intangible product (e.g. the income statement needed to prepare a taxreturn);- the delivery of an intangible product (e.g. the delivery of information in the context of knowledge transmission);- the creation of ambience for the customer (e.g. in hotels and restaurants).NOTE 2 Adapted from ISO 9000:2005, definition 3.4.2, Note 2.
The length of time between the target placement and when the canine is deployed to detect the target scent.
The length of time between the target placement and when the canine is deployed to detect the target scent.
The length of time between the target placement and when the canine is deployed to detect the target odor/scent.
An arc site where one or more of the circuit conductors were physically severed by the arcing event at that location.
the portion of the hair emerging from the hair follicle.
the portion of the hair emerging from the hair follicle.
the shape of the hair both longitudinally (for example, curly, straight) and cross-sectionally (for example, round, flattened).
the shape of the hair both longitudinally (for example, curly, straight) and cross-sectionally (for example, round, flattened).
the diameter of the hair.
Discussion—This is expressed either numerically or in relative terms, such as fine, medium, or coarse.
Used to indicate that a provision is mandatory. (unless otherwise documented for non-compliance).
Indicates a mandatory requirement.
an explosive charge configuration incorporating a liner, usually metal, shaped so as to concentrate its explosive force in a particular direction in order to cut or penetrate.
The process of selectively rewarding responses that approximate the desired behavior to an increasingly greater degree. This is one method for teaching a new behavior and can be used as a method of modifying additional behaviors. (See approximation.)
A tendency to react to stimuli with aggressive behavior.
in image and video analysis, a process used to emphasize edge detail in an image by enhancing the high-frequency components.
elongated crystals form two opposite fans from the same joining point.
a flexible high-explosive charge having mixtures of PETN or RDX and nitrocellulose with rubber polymers and plasticizers.
Discussion—These are also known as Detasheet, Det Sheet, or Flex-X, and are typically less malleable than most Semtex or C-4.
a small-diameter plastic tube with the interior walls coated with a very thin layer of energetic material (most commonly HMX and aluminum powder) that, when initiated, transmits a detonation.
Utilizing a canine to locate target odors in a shoreline environment.
An abnormal connection of low resistance between normal circuit conductors where the resistance is normally much greater; this is an overcurrent situation but it is not an overload.
Multiple copies of an identical (or similar) DNA sequence arranged in direct succession where the repeat sequence unit is 2 base pairs (bp) to 6 bp in length; because STRs generally occur in the DNA outside of the constraints (i.e., selective pressure) of genes, the number of repeat units can vary between individuals;2 variations in STRs may be used for distinguishing individuals, and in biological relationship and ancestry testing
Used to indicate that a provision is not mandatory, but recommended as good practice.
Indicates a recommendation or that which is advised but not required.
a variation of the hair form along the shaft, resulting in an irregular and often asymmetrical change of cross-sectional shape.
a variation of the hair form along the shaft, resulting in an irregular and often asymmetrical change of cross-sectional shape.