GRAFOTYPProject financed by

the Ministry of Science and Higher Education in Polandfrom funds on science in years 2009 – 2011 as development project

Authors of software:Andrzej Łuszczuk M.Sc.

Krystyn Łuszczuk M.Sc. Eng.

Scientific consultation:Prof.Tadeusz Tomaszewski

Dr Mieczysław Goc

English version:Agnieszka Łukomska (M.A.)

Software producer and distributor:

Research and Training Centreof Polish Forensic Association

www.kryminalistyka.pl

Programme Guide

The PolishForensicAssociation

Universityof Warsaw

The programme applies: graphometrical examined method, basic notions: shape coefficient, size proportion, Grafotyp, Grafotypes match.

Which were worked out by authors of programme.

System and equipment requirements:

TO ENSURE PROPER RUNNING OF PROGRAMMETHE FOLLOWING REQUIREMENTS SHOULD BE MET:

1. Operating system: Windows XP, Windows Vista, Windows 7 or Windows 8.

2. IMPORTANT: required monitor (display) resolution 1024 × 600 or higher. In lower resolution, the programme cannot be started.

3. Recommended default font size "9" at 96 dpi (not more than 120 dpi).

4. In Windows „.NET Framework" platform in v.2.0.50727 or more recent version should be installed. It is necessary for proper running of the programe.

Definitions:

G = Wk × Pw

Specimens - corresponding fragments of handwriting "A" and "B" selected for analysis,e.g. syllable, morpheme, word, illegible construction (signature).

Shape coefficient (Wk) - structural parameter of handwriting expressed through quotientof area of a polygon, constituting "contour" of the area of specimen selected for analysis

(questioned and reference material) by square circumference of that polygonWk = Σ | F | / (ΣL^2). For specimen A - shape coefficient (Wka)

and for specimen B - shape coefficient (Wkb).

Size proportion (Pw) - quotient of lenghts (shorter to longer) of two, most characteristic segments in specimens "A" and "B" (horizontal, vertical or slanting) set according to the same criteria, i.e. these segments should link corresponding points in specimens "A" and

"B".Grafotyp (G) - structural property of handwriting, individualizing its writer.

Mathematically it constitutes a product of shape coefficient (Wk) and size proportion (Pw).

Grafotyp similarity (%) - percentage rate of structural shape similarity between specimens "A" and "B", which demonstrates the authorship similarity. Mathematically it constitutes

a quotient of Grafotypes (lower to higher value) multiplied by 100%.

l15

l17

l6

l5l4l3

l2l1

l13 l12 l11 l10l9

l8

l7

l16 l14

Circumference „of contour” P = l1+l2+l3+…+l15+l16+l17 (sum of lenghts of red segments)

Shape coefficient Wk = 100 * F / P²

Size proportion Pw = W1 / W2 , where: 0 < Pw <= 1

Surface (green) „of contour” = F

GRAFOTYP G = Wk × Pw

W2

W1

F

GRAFOTYP – method of calculation

GRAFOTYP

GRAFOTYP allows for evaluation of degree of similarity between handwriting specimens basing on the following:

1. Shape coefficients match Wk2. Size proportion Pw3. Grafotypes match G

GRAFOTYP – interface(specimens prepared for examination)

Specimens after analysis – positive verification

Shape coefficients match

Grafotypes match

Shape coefficient of specimen A

Shape coefficient of specimen B

Message of quantile test

Shape coefficient of specimen A

Shape coefficient of specimenB

Shape coefficients match

Grafotypes match

Message of quantile test

Specimens after analysis – negative verification

Notes on statistical test applied:

A quantile statistical test, used in the programme, is entirely independent from Wk, Pw values calculated before and Grafotypes. It is necessary for the

specimen "contour" polygon to have from 6 up to 30 (optimally around 20) sides.

Quantile test constitutes a separate examination method. If the test demonstrates a proper distribution of quotients of corresponding

sides, this may attest for a match of shapes of specimens’ „contours”. The test helps expert in making such decision.

Furthermore, the test serves as a certain verification of earlier measurements.

If, for instance, the test will show the possibility of match between specimens at low Grafotype similarity, this provides for inaccurate or wrong designation of

"contours", W1-W2 segments in particular.In such instances the analysis should be repeated.

The following messages of quantile test can appear as result of analysis:

Basic principles of verification of handwriting

specimens in GRAFOTYP

Statistical certainty of verification increases with the number of sides in „contour” polygons.

GRAFOTYP is a measuring tool, which examines geometrical shape of specimens. It does not account for other features

(such as tremor, points of stoppage, shading distribution) which may appear in examined specimens and be in conflict with high

geometrical similarity.

PROGRAMME IS A MEASURING TOOL AND DOES NOT INTEND TO SUBSTITUTE THE EXPERT

A final decision on match of examined entries belongs to the user !!!

You are welcome to use our programme