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.
Semantic Conformance
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.
Sensitive Periods
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.
Sensitivity Coefficients
The partial derivatives of a measurement function that describe how the measurand's value varies with changes in the values of the input quantities.
Sensitivity Studies
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.
Sensitivity Studies
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.
Sensitivity Studies
Studies performed to assess the ability of the probabilistic genotyping system to support the presence of a known contributor
sensitivity studies
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.
Sensitizer
Sensory Threshold
The amount of stimuli that is necessary to produce a response from the canine.
sequence identity
The percentage or number of nucleotides or amino acids that are identical between two sequences.
Sequencing (Dna)
A laboratory technique used to determine the sequence of bases (A, C, G, and T) in a DNA molecule.
sequencing (DNA)
A laboratory technique used to determine the sequence of bases (A, C, G, and T) in a DNA molecule.
sequencing (Sanger sequencing)
A method of DNA sequencing for determining the order of bases in a DNA molecule based on the selective incorporation of chain-terminating dideoxynucleotides by DNA polymerase during in vitro DNA replication.
sequencing, DNA
A laboratory technique used to determine the sequence of bases (A, C, G, and T) in a DNA molecule.
serology
The detection and/or taxonomic identification of body tissues and fluids, through the use of chemical reagents and antibody/antigen reactions.
Serum Stain
Service
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.
set off
The unintentional transfer of part of an image or ink from its intended location to another surface. (ASTM F221)
Set Time
The length of time between the target placement and when the canine is deployed to detect the target odor/scent.
Sever Arc
An arc site where one or more of the circuit conductors were physically severed by the arcing event at that location.
sex
A set of biological attributes, such as chromosomes, gene expression, and/or physiological functions that influence skeletal expressions across the spectrum of sexual dimorphism.
sex assigned at birth
Classification of male or female provided by a physician at birth based on external genitalia; typically aligns with skeletal expressions across the spectrum of sexual dimorphism.
sexual assault
physical, sexual activity without the consent of the other person or when the other person is unable to consent to the activity.
Discussion—The activity or conduct may include physical force, violence, threat, intimidation, ignoring the objections of the other person, causing the other person’s intoxication or incapacitation (through the use of drugs or alcohol) or taking advantage of the other person’s intoxication (including voluntary intoxication).
shading
Variations in the line width or density resulting from changes in the pressure of the writing instrument on the document; also associated with variations in pressure when using a split nib pen. Also referred to as stress.
Shaft
Shaft Form
Shaft Thickness
Shall
Indicates a mandatory requirement.
Shaped Charge
Shaping By Successive Approximation
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.)
sharp trauma
A skeletal defect produced by an object that is edged, pointed, or beveled.
Sharpening
Sharpness
A tendency to react to stimuli with aggressive behavior.
Sheaves
Sheet Explosive
Shell Tire Mold
Shock Tube
Shoe Perimeter
Shoe Size
Shoe Size Grading
shooting reconstruction
A scene reconstruction focused on the discharge of a firearm(s).
Shoreline Search
Utilizing a canine to locate target odors in a shoreline environment.
Short Circuit
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.
Short Tandem Repeats Str
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
Should
Indicates a recommendation or that which is advised but not required.
Shoulder
Shouldering
Shrapnel
side lighting
Illumination from a light source at a low angle of incidence, or even parallel, to the surface of the item. Syn. oblique lighting, grazing illumination, raking lighting. (ANSI/ASB Std 044)