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.
An algorithm that allows signals with a large dynamic range to be transmitted overfacilities with a smaller dynamic range. It is used in telephony (see -law and A-law)and some other types of communications
The process of examining two or more DNA data sets to assess the degree of similarity or difference.
The process of examining two or more DNA data sets to assess the degree of similarity or difference.
The process of examining two or more DNA data sets to assess the degree of similarity or difference.
A series of computational steps which seeks to assess both the level of geometric similarity (similarity of toolmarks) and the degree of certainty that the observed similarity results from a common origin. A comparison algorithm makes use of a scoring function or similarity score.
a system of two microscopes positioned side-by-side and connected via an optical bridge so that two specimens are examined simultaneously in a single field of view in either transmitted or reflected light.
fire debris, (1) a sample of material collected from a fire scene which is, to the best of the collector's knowledge, similar with respect to relevant characteristics to a sample suspected of containing ignitable substance, but which is not expected to contain an ignitable substance; (2) a sample of suspected ignitable substance submitted for the purpose of comparing with any ignitable substance separated from a debris sample.
Discussion—A comparison sample should not be confused with a control sample. For example, a comparison sample might include unburned carpet or flooring that meets the requirements in (1).
Discussion—Although, in theory, the use of comparison samples can help clarify the presence of a suspected inherent ignitable liquid, the presence of an ignitable liquid in a comparison sample does not necessarily mean it is inherent to the material.
Software that implements a comparison algorithm and may also include database, search, and visualization functionality.
any variety of optical devices that can be placed in the light path of a polarized light microscope to introduce known, fixed or variable retardation in a specific vibration direction; the retardation and sign of elongation of the fiber can then be determined.
a compensator (usually a plate of gypsum, selenite or quartz) that introduces a fixed retardation between 530 to 550nm (approximately the retardation of the first order red color on the Michel-Levy chart).
a compensator (usually a mica plate) that introduces a fixed retardation between ~137–147nm (approximately the retardation of first-order gray on the Michel-Levy chart).
a wedge, usually cut from quartz, having continuously variable retardation extending over several orders (usually 3 to7) of interference colors.
a quarter-wave plate inserted above the specimen in the parallel "0" position with a calibrated rotating analyzer; measures low retardation and requires the use of monochromatic light.
a compensator typically containing a plate of calcite or quartz, which can be tilted by means of a calibrated drum to introduce incrementally variable retardation.
Demonstrated and documented ability of an individual to perform assigned work in a discipline or subdiscipline, in accordance with a laboratory's technical procedures and training manuals, before the performance of independent casework.
The demonstration of technical skills and knowledge necessary to perform forensic DNA analysis successfully.
demonstration that a forensic science practitioner has acquired and demonstrated specialized knowledge, skills, and abilities (KSAs) in the standard practices necessary to conduct examinations in a discipline or category of testing prior to performing independent casework
demonstration that a forensic science practitioner has acquired and demonstrated specialized knowledge, skills, and abilities (KSAs) in the standard practices necessary to conduct examinations in a discipline or category of testing prior to performing independent casework.
demonstration that a forensic science practitioner has acquired and demonstrated specialized knowledge, skills, and abilities (KSAs) in the standard practices necessary to conduct examinations in a discipline or category of testing prior to performing independent casework
A person having suitable or sufficient skill, knowledge, and experience to train canines and canine handlers, who has demonstrated, through education, training, and operational experience, extensive skills and knowledge in the subject field or discipline. This person would normally perform the maintenance training and proficiency training in the field and may train canines in preparation for a formal course of instruction.
A person having suitable or sufficient skill, knowledge, and experience to train canines and canine handlers, who has demonstrated, through education, training, and operational experience, extensive skills and knowledge in the subject field or discipline. This person would normally perform the maintenance training and proficiency training in the field and may train canines in preparation for a formal course of instruction.
A person having suitable or sufficient skill, knowledge, and experience to train canines and canine handlers, who has demonstrated, through education, training, and operational experience, extensive skills and knowledge in the subject field or discipline. This person would normally perform the maintenance training and proficiency training in the field and may train canines in preparation for a formal course of instruction.
A person having suitable or sufficient skill, knowledge, experience to train canines and canine handlers.
A person having suitable or sufficient skill, knowledge, experience to train canines and canine handlers.
An ignition source that has sufficient energy and is capable of transferring that energy to the fuel long enough to raise the fuel to its ignition temperature. (See 19.4.2.)
A test designed to establish that an individual has demonstrated achievement of technical skills and met minimum standards of knowledge necessary to perform forensic DNA analysis.
Evaluation of a persons knowledge and ability to perform work before authorization to do so independently.
A test used to demonstrate an individual's ability to successfully conduct an examination(s) prior toperforming casework.
A person having suitable or sufficient skill, knowledge, and experience to train canines and canine handlers, who has demonstrated, through education, training, and operational experience, extensive skills and knowledge in the subject field or discipline. This person would normally perform the maintenance training and proficiency training in the field and may train canines in preparation for a formal course of instruction.
Expression of dissatisfaction, other than appeal, by any person or organization to an inspection body, relating to the activities of that body, where a response is expected
expression of dissatisfaction, other than appeal, by any person or organization to an inspection body, relatingto the activities of that body, where a response is expectedNOTE Adapted from ISO/IEC 17000:2004, definition 6.5.
expression of dissatisfaction by any person or organization to a laboratory (3.6), relating to the activitiesor results of that laboratory, where a response is expected[SOURCE: ISO/IEC 17000:2004, 6.5, modified The words other than appeal have been deleted, andthe words a conformity assessment body or accreditation body, relating to the activities of that bodyhave been replaced by a laboratory, relating to the activities or results of that laboratory.]
An expression of dissatisfaction by any person or organization to an organization relating to its product or service, or the complaints-handling process itself, where a response or resolution is explicitly or implicitly expected. Complaints can be written, electronic, or oral, and may originate internally or externally.
A characteristic of a comparison in which the attributes of one or both impressions may require additional consideration and quality assurance measures relating to the evaluation of a source conclusion.
A characteristic of an impression whose attributes may require additional consideration and quality assurance measures.
Sophisticated computer programming that contains multiple interconnected modules or components. Complex software systems have components whose interactions evolve. The set of possible states of the system can be infinite, unbounded, and most importantly, changing.
Detailed features of the facial components
a single analog video signal that combines a base-band luminance signal with color information by modulating a subcarrier with chroma signals, typically using one of the National Television System Committee (NTSC), Phase Alternating Line (PAL), or Sequential Color with Memory (SECAM) systems.
a process to reduce the size of a data file or stream while attempting to retain the original semantic meaning of that data.
the ratio of the size of the data before compression to that of after compression.
the scientific examination, analysis, or evaluation of digital evidence in legal matters.
system containing one or more components and elements such as computers (hardware), associated software, and data (e.g., software, firmware, hardware, configuration files) f
f: ISO/IEC 25024:2015(en) Systems and software engineering — Systems and software Quality Requirements and Evaluation (SQuaRE) — Measurement of data quality available from ANSI.
The canine's focus on the area of search (further specification will be discipline specific).
The amount of a constituent expressed as a mass or volume divided by the total amount of material expressed as a mass or volume.
Opinion stated by an examiner after interpretation of observed data. The opinion is the personal judgement that the observed data can offer support for one proposition over another. A conclusion is distinct from a “proposition.”
Analyzed at or close to the same time under the same analytical conditions (i.e., same instrument and instrumental parameters).
Analyzed at or close to the same time under the same analytical conditions (e.g., same instrument and instrumental parameters).
metal strip mounted on a holder that is inserted into the column under the condenser lenses: the strip can have three selectable holes or one fixed hole that the electron beam passes through the center and stray electrons are then captured by the surrounding plate.