Nine-Point Opinion Scale
Definition
The standard framework used by the ASQDE and most international document-examination organisations for expressing conclusions, ranging from identification through elimination with intermediate degrees of probability.
- Adopted by
- ASQDE and most international document-examination bodies
- Range
- Identification through elimination
- Structure
- Intermediate degrees of probability between the poles
Common questions
Why use a nine-point graded scale instead of a simple yes or no conclusion?+
Handwriting and document comparisons often yield evidence of varying strength, so the graded scale lets an examiner report a qualified opinion, such as probable or indications of, when the evidence does not support a categorical identification or elimination.
Does every document examiner internationally use the same nine categories?+
Most international organisations follow a closely similar scale, but exact wording and category boundaries can differ slightly between professional bodies, so the examiner's report should state which scale and terminology was applied.
How should a court interpret a mid-scale opinion such as 'probably did'?+
A mid-scale conclusion signals that the examiner found supporting but not conclusive evidence, and it should be weighed alongside other case evidence rather than treated with the same certainty as a categorical identification at either end of the scale.
Related terms
- Chemical Erasure
- Destruction of an ink's chromophore by oxidising or reducing agents (bleach, permanganate, borohydride) without physically removing paper fibres, leaving altered UV fluorescence...
- Chromophore
- The molecular subunit responsible for a dye's colour, typically a conjugated double-bond system; chemical erasure destroys the chromophore while leaving the decolourised...
- Interlineation
- Text inserted between existing lines of a document after its original execution; may be detected by ink composition differences, spatial anomalies in...
- Mechanical Erasure
- Physical removal of ink by abrasion (eraser) or shearing (blade), leaving disrupted paper fibres, altered surface texture, and residual ink in fibre...
- Obliteration
- Covering of existing writing with an opaque layer (ink, correction fluid, or correction tape) so that the underlying text is invisible in...
- Page Substitution
- Replacement of one or more pages in a multi-page document with forgeries, detectable through paper batch inconsistencies (UV fluorescence, watermark), printing differences,...
- Sizing
- Chemicals applied to paper during manufacture to control ink absorption and surface hardness; mechanical erasure removes sizing from the affected area, allowing...
- SWGDOC
- The Scientific Working Group for Forensic Document Examination (US), which publishes standards for typewriter examination, handwriting comparison, ink analysis, and related forensic...
- Titanium Dioxide (TiO2)
- The white pigment in most correction fluids worldwide; opaque in visible light but largely transparent above ~800 nm near-IR, making IR transmission...