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.
Background
Background
Background radiation
Background Sample
Backing
Backlight
Backlit
Backscattered Electron (BE) Imaging
Backsize
Backspatter Pattern
Backup Handler Canine
A canine that is trained, certified, and/or works with more than one certified canine handler.
ball element
An element used in a single element typewriter in which the fully formed characters are located on the outer surface of a spherelike device. Frequently called golf ball element. (SWGDOC E04-13)
Ball powders
ball terminal – typewriting
Small round globe on some typefaces.
ballistics
The science of projectiles in motion. Usually divided into three parts:
ballpoint pen ink
Writing or marking media intended for use in a ball point pen. Typically, a thick, high viscosity ink with an oil, glycol, or rubber base. (SWGDOC M01)
Band
banding
Uniform density variations or voids in a given color which appear in the direction that the printhead travels. (ASTM F1857)
Barcode of Life Database (BOLD)
Nucleotide sequence database devoted to taxonomic studies and online platform for DNA sequence analysis of cytochrome oxidase I data.
Bark Props
Items used to conceal a target source in order to test the canine to perform the bark indication.
Barrier filter
base
The lowest element of letters such as the capital letters “E” and “L".
Base Charge
Base Peak
Base Rate Baseline
The normal frequency of occurrence of a specified response per unit of time for that individual canine or group of canines.
baseline
The ruled or imaginary line upon which writing, typographic printing, or typewriting appears to rest.
Basic Local Alignment Search Tool (BLAST)
The a) BLAST algorithm, and b) a suite of database search programs that implement variations of this algorithm to generate alignments between a nucleotide or protein sequence in a query, and nucleotide or protein sequences within a database.
Basic Local Alignment Search Tool (BLAST)
Refers to a) the BLAST algorithm, and b) a suite of database search programs that implement variations of this algorithm to generate alignments between a nucleotide or protein sequence in a query, and nucleotide or protein sequences within a database.
Batch Mode Search
Batch Search Mode
batch to batch variation
Within an ink formulation, difference in the concentration of a component of an ink formula due to deviations during production that are within the manufacturer’s tolerance limit. (SWGDOC M01)
BCOE
The FBI's Biometric Center of Excellence.
BDB
Biometric Data Block used in CBEFF.
Bead
A rounded mass of resolidified metal on the end of the remains of an electrical conductor or conductors that was caused by arcing and is characterized by a sharp line of demarcation between the melted and unmelted conductor surfaces.
Bead
bead defect
Inked or un-inked impression or hole in the paper caused by a contaminant particle encased in plating material located on or adjacent to the printing area of the typeface on a metal coated element. (SWGDOC E04)
Beam current
Becke line
a halo observed near the boundary of a transparent particle that is mounted in a medium that differs from the particle’s refractive index.
Becke line method
method for determining the refractive index of a transparent particle relative to its mountant by noting the direction in which the Becke line moves when the focus is changed.
DISCUSSION—The Becke line always moves toward the higher refractive index medium (particle or mountant) when the focus is raised, and towards the lower refractive index medium when the focus is lowered. At the point where the index of the particle matches the index of the mounting medium, the Becke line is no longer visible. The Becke line is generally viewed at a wavelength of 589 nm (the D line of sodium [nD]).
Behavior
Any measurable, physical response of a canine. Can be voluntary (goal directed) or involuntary (reflexive).
Behavior Modification
The application of a behavioral technique (e.g., positive reinforcement) to change a behavior.
Behavioral Chain
A series of independent behaviors that are linked together.
bench trial
A trial where the judge sits as the trier of fact.
Berdan primer
Best Practices
A system of processes, checks and testing that may deliver an outcome that has fewer problems and fewer unforeseen complications, and that may combine the attributes of the most efficient and most effective ways of accomplishing a task based on proven and provable methods, while maintaining overall operational integrity and remaining within the bounds of legally accepted practices.
beta (β)
symbol representing the intermediate principal re- fractive index of a biaxial crystal.
Bias
Preconception; prejudice; taint; partiality. Since most persons have biases, the issue is whether the bias is such that impartiality cannot be achieved and a fair outcome cannot occur. Any predisposition that a judge or arbitrator may have may be grounds for recusal. Any predisposition that a witness may have may be grounds for impeachment by cross-examination. Any predisposition that a juror may have may be grounds for excusal determined by through a process known as voir dire. This use of the term 'bias' is not that as used in statistical evaluations. (See cognitive bias, contextual bias, and experimental bias.)
Bias
The variance of measured results as influenced by human perceptions or systemic factors. Note: It is beyond the scope of this document to outline the numerous types of biases
bias
Any factor that has the potential of causing systematic deviation from any part of an evaluative process.
bias (cognitive)
tendency for an individual’s preexisting beliefs, expectations, motives, or the situational context to influence their sampling, observations, results, interpretations, or opinions, or their confidence in the aforementioned