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.
the portion of the hair closest to, and including, the root.
The segment of the finger or thumb closest to the palm.
operator-selected value for the time designated to record a response by the detector.
Discussion—A higher value (longer time) results in a more accurate determination of the detector amplifier pulse height (better spectral resolution). A lower value results in a higher count rate but with reduced spectral resolution.
operator-selected value for the time designated to record a response by the detector. A higher value (longer time) results in a more accurate determination of the detector amplifier pulse height (better spectral resolution). A lower value results in a higher count rate but with reduced spectral resolution.
The action of the pupils constricting in response to light, it requires vision and normal neurologic control of the pupils
The action of the pupils constricting in response to light, it requires vision and normal neurologic control of the pupils.
a chromatogram obtained from the pyrolysis products of a material.
Product of decomposition through heat; a product of a chemical change caused by heating.
to undergo pyrolysis; also known as pyrolyze.
product of decomposition through heat; a product of chemical change caused by heating; also known as pyrolyzate or pyrolysis product.
to undergo pyrolysis; also known as pyrolyze.
A process in which material is decomposed, or broken down, into simpler molecular compounds by the effects of heat alone; pyrolysis often precedes combustion.
the thermal fragmentation of a substance in an inert atmosphere.
a process in which organic material is broken down into simpler molecular compounds by the effects of heat alone; pyrolysis often precedes combustion.
the temperature (set or ramped) at which the pyrolysis of the sample is performed.
the product of the pyrolysis process.
Any substance that spontaneously ignites upon exposure to atmospheric oxygen.
Any substance that spontaneously ignites upon exposure to atmospheric oxygen.
any substance that spontaneously ignites upon exposure to atmospheric oxygen.
A method of DNA sequencing which is performed by detecting the nucleotide incorporated by a DNA polymerase.
A method of DNA sequencing which is performed by detecting the nucleotide incorporated by a DNA polymerase.
a mixture of chemical substances which, on burning, produces bright or colored light, heat, smoke, or acoustic effects.
Discussion—Pyrotechnic mixtures can cause an explosion if ignited while confined.
a pellet of pyrotechnic material that contributes to the patterns and effects of an aerial firework.
Discussion—Pyrotechnic stars can come in a variety of sizes, but are generally spherical or cylindrical in shape.
A linear regression of polynomial degree 2
a generic term for a four-legged camera support.
An adjective used to describe an individual who meets the requirements for the position, has successfully completed the laboratory's applicable training requirements, and is authorized to perform a specific task or role.1
chemical, analysis in which substances are identified or classified on the basis of their chemical or physical properties, such as chemical reactivity, solubility, molecular weight, melting point, radiative properties (emission, absorption), mass spectra, nuclear half-life, and so forth (see also quantitative analysis).
An assay designed to be more specific for targeted analytes and based on a different chemical principle than a screening method
An ordinal estimate of the usefulness of biometric data for the purpose of automatedrecognition.
That part of quality management focused on providing confidence that quality requirements will be fulfilled.
All the planned and systematic activities implemented within the quality system, and demonstrated as needed, to provide adequate confidence that an entity will fulfill requirements for quality.
all the planned and systematic activities implemented within the quality system, and demonstrated as needed, to provide adequate confidence that an entity will fulfill requirements for quality.
That part of quality management focused on fulfilling quality requirements.
Materials used to prepare control samples including reference materials, certified reference materials, and blank matrix samples
A component of a quality assurance program that focuses on ensuring accuracy in laboratory test results through careful monitoring of test methods
Part of quality management focused on increasing the ability to fulfil quality requirements. The requirements can be related to any aspect such as effectiveness, efficiency, or traceability.
The coordinated activities to direct and control an organization with regard to quality. Direction and control with regard to quality generally includes establishment of the quality policy and quality objectives, quality planning, quality control, quality assurance, and quality improvement.
That part of quality management focused on setting quality objectives and specifying necessary operational processes and related resources to fulfil the quality objectives.
chemical, analyses in which the amount or concentration of an analyte may be determined (estimated) and expressed as a numerical value in appropriate units.
Discussion—Qualitative analysis may take place without quantitative analysis, but quantitative analysis requires the identification (qualification) of the analytes for which numerical estimates are given.
any process used to extract measurable data from an image.
the minimum amount that can be quantitated with acceptable accuracy and precision.
An assay designed to measure the concentration of an analyte within a sample
A means for quantifying the amount of nucleic acid present in a sample using PCR.
A systematic search of an area in a series of point-to-point patterns utilizing the wind to the canine's best advantage.
(n) The nucleotide or protein sequence that has an unknown source (i.e., evidence sequence), or (v) the action of searching an unknown sequence against a database.
The percent of the query sequence length that is included in the aligned segment with a hit.
associated with the matter under investigation about which there is some question, including, but not limited to, whether the questioned and known items have a common origin.
in image analysis and facial identification, an image of an individual or object whose identity is unknown or in question and has been recorded electronically or by other medium. (Compare known image.)
An item of unknown source (impression or otherwise) that is normally recovered from a crime scene.