OSAC 2022-S-0034 Standard for the Expression of

Conclusions in Forensic Document Examination

1

OSAC 2022-S-0034 

Standard for the 

Expression of Conclusions 

in Forensic Document

Examination

Forensic Document Examination Subcommittee

Physics/Pattern Interpretation Scientific Area Committee

Organization of Scientific Area Committees (OSAC) for Forensic Science
OSAC 2022-S-0034 Standard for the Expression of

Conclusions in Forensic Document Examination

2

Draft OSAC Proposed Standard

OSAC 2022-S-0034 

Standard for the 

Expression of Conclusions 

in Forensic Document

Examination

Prepared by 

Forensic Document Examination Subcommittee

Version: 1.0 - OSAC Open Comment

August 2022

Disclaimer:

This OSAC Proposed Standard was written by the Organization of Scientific Area Committees 

(OSAC) for Forensic Science following a process that includes an open comment period. This 

Proposed Standard will be submitted to a standards developing organization and is subject to 

change. 

There may be references in an OSAC Proposed Standard to other publications under 

development by OSAC. The information in the Proposed Standard, and underlying concepts and 

methodologies, may be used by the forensic-science community before the completion of such 

companion publications.

Any identification of commercial equipment, instruments, or materials in the Proposed Standard 

is not a recommendation or endorsement by the U.S. Government and does not imply that the 

equipment, instruments, or materials are necessarily the best available for the purpose.
OSAC 2022-S-0034 Standard for the Expression of

Conclusions in Forensic Document Examination

3

To be placed on the OSAC Registry, certain types of standards first must be reviewed by a 

Scientific and Technical Review Panel (STRP). The STRP process is vital to OSAC’s mission of 

generating and recognizing scientifically sound standards for producing and interpreting forensic 

science results. The STRP shall provide critical and knowledgeable reviews of draft standards or 

of proposed revisions of standards previously published by standards developing organizations 

(SDOs) to ensure that the published methods that practitioners employ are scientifically valid, 

and the resulting claims are trustworthy.

The STRP panel will consist of an independent and diverse panel, including subject matter 

experts, human factors scientists, quality assurance personnel, and legal experts, which will be 

tasked with evaluating the proposed standard based on a comprehensive list of science-based 

criteria.

For more information about this important process, please visit our website 

at: https://www.nist.gov/topics/organization-scientific-area-committees-forensicscience/scientific-technical-review-panels.
OSAC 2022-S-0034 Standard for the Expression of

Conclusions in Forensic Document Examination

1

Foreword

The use of standardized terminology by Forensic Document Examiners (FDEs), like other 

forensic science service providers, promotes consistency across jurisdictions and relieves the 

judicial system of conflicting terms and definitions when an examiner is reporting written 

conclusions or testifying. Some terms and definitions in this document might vary from the 

usage of other forensic disciplines.

Table of Contents

1 Scope.....................................................................................................................................................................................1

2 Normative	References...................................................................................................................................................1

3 Terms	and	Definitions...................................................................................................................................................1

4 Requirements....................................................................................................................................................................2

5 Conclusions........................................................................................................................................................................2

Annex	A	(informative)	Bibliography.................................................................................................................................6

1 Scope

This document provides standardized terms, definitions, and usage examples relevant to 

expressing the conclusions of FDEs. This standard may not cover all wording or conclusions 

given for unusual or uncommon examinations.

2 Normative References

None

3 Terms and Definitions

3.1 conclusion

A position reached after consideration of a set of facts or examination results.

3.2 proposition

statement or assertion that is either true or false. Propositions represent two or more competing 

explanations for the evidence in the case at hand. As such, they are mutually exclusive, meaning 

they cannot be true at the same time.

Example of two mutually exclusive propositions:

1: John Doe wrote the questioned item

2: Someone other than John Doe wrote the questioned item
OSAC 2022-S-0034 Standard for the Expression of

Conclusions in Forensic Document Examination

2

3.3 intelligence conclusions or results

provide indicators (based on physical remnants of events) to link cases, events, and situations in 

the form of strategic intelligence. These conclusions address questions relating to phenomena 

and may be in the form of analytical products (such as crime pattern) or intelligence products 

(such as specific crime series to inform decisions on the prioritization of problems and targets).

3.4 investigative conclusions or results

provides possible explanations for technical findings. These types of conclusions are given when 

a pair of competing propositions have not been formulated. This happens when there is 

insufficient background (conditioning) information or when the submitter requests explanations 

for findings and there is no obvious alternative.

3.5 technical conclusions or results

descriptive account of findings. In certain situations, this may constitute the assignment of an 

item to a class (i.e., classification). A technical conclusion does not involve a formal evaluation, 

under a pair of competing propositions.

4 Requirements

4.1 Not Suitable Determination

4.1.1 When an item(s) is unsuitable for continued examination, language similar to the 

following should be used: 

“The submitted item(s) does not provide a sufficient basis for a meaningful comparison 

or evaluation to address the specific request.”

5 Conclusions

Conclusions can be evaluative, meaning they address at least two propositions, or non-evaluative 

in nature. Expert conclusions are based on observations regarding characteristics or features of 

the item(s), evaluated using the knowledge, education, training, and experience of the examiner. 

A statement to this effect serves to clarify the bases of the conclusions stated below. These 

statements should be presented in the broader context of a comprehensive examination and 

report.

The conclusions are based upon the information and materials provided to the examiner, as well 

as the propositions used in the examination. If the information or materials change, or should 

different propositions be of interest, then the conclusion(s) may also change.

5.1 Evaluative Conclusions
OSAC 2022-S-0034 Standard for the Expression of

Conclusions in Forensic Document Examination

3

5.1.1 Evaluative conclusions shall be expressed following a complete evaluation (1) within a 

framework of relevant contextual information, (2) by considering at least two competing 

propositions, and (3) with a focus on the evaluation of findings given each proposition. 

5.1.2 Evaluative conclusions are intended to convey the degree of support provided by the 

findings for one proposition relative to one or more specified alternative propositions. The 

conclusion shall be worded as follows:

“The findings provide <modifier> support for proposition X relative to proposition Y.” 

As an alternative to “findings,” “evidence” or “observed combination of characteristics” 

may be used.

5.1.3 The <modifier> conveys the magnitude of the degree of support the findings provide for 

proposition X relative to proposition Y. Either proposition can be first in the above statement 

according to whichever is favored. The modifier will be:

• Extremely strong

• Very strong

• Strong

• Moderate

• Limited

• Approximately equal 

5.1.4 When the modifier is Limited and to avoid the “weak evidence effect,” 1 the examiner’s 

conclusion should be stated similarly to the following: “The findings provide more support for 

proposition X than for proposition Y, but the amount/level of that support is limited.” 

5.2 Modifier Meaning

5.2.1 A conclusion of equal support for proposition X relative to proposition Y means that the 

findings provide approximately the same degree of support for both propositions. This may be 

clarified as an indeterminable conclusion. Each progressive level (“limited,” “moderate,” 

“strong,” “very strong,” “extremely strong”) represents an incremental increase in the degree of 

support. The modifiers used to differentiate the gradations of levels should not be considered as 

clearly defined categories.

Note: Examiners using the ENFSI or NIFS guidelines define this increase as approximately 

tenfold. This level of increase is similar to the Richter scale for earthquakes.

5.2.2 Acceptable alternative wording that may be used:

1 Martire KA, Kemp RI, Watkins I, Sayle MA, Newell BR. The expression and interpretation of uncertain forensic 

science evidence: verbal equivalence, evidence strength, and the weak evidence effect. Law Hum Behav. 2013 

Jun;37(3):197-207. doi: 10.1037/lhb0000027. PMID: 23750600.
OSAC 2022-S-0034 Standard for the Expression of

Conclusions in Forensic Document Examination

4

“<modifier> support if X is true than if Y is true”

“<modifier> support given X than given Y” 

“<modifier> support for X rather than Y”

“approximately equal support given both X and Y”

5.2.3 Examples for handwriting conclusions, given the following propositions:

Proposition 1: The writer of the K1 samples wrote the Q1 handwriting.

Proposition 2: Someone other than the writer of the K1 samples wrote the Q1 

handwriting.

Example 1: “The findings provide moderate support for the Q1 and K1 samples having 

been written by the same writer relative to having been written by different writers.”

Example 2: “The findings provide strong support for the Q1 and K1 samples having been 

written by different writers relative to having been written by the same writer.”

5.2.4 Examples for non-handwriting conclusions, given the following propositions:

Proposition 1: The questioned document was produced by the submitted typewriter.

Proposition 2: The questioned document was produced by a typewriter other than the 

submitted typewriter.

Example 1: “The findings provide extremely strong support for the questioned document 

having been produced by the submitted typewriter relative to having been produced by a 

different typewriter. 

Example 2: “The findings provide more support for the questioned document having been 

produced by the submitted typewriter relative to having been produced by a different 

typewriter, and the amount of that support is limited.”

5.3 Non-evaluative conclusions and results 

Non-evaluative conclusions or results are used to describe observations, assign an object to a 

class, provide guidance, or assess the findings under a single proposition. These are often 

distinguished as being technical, investigative, or intelligence conclusions. 

5.3.1 Non-evaluative conclusions shall not be used for comparative handwriting examinations.

5.3.2 Examples

Example 1: The questioned document was printed by a toner device. The printed 

characteristics do not correspond to other known printing technologies.

Example 2: The following indented writing recovered on the questioned document reads

“150 N. Los Angeles St.”
OSAC 2022-S-0034 Standard for the Expression of

Conclusions in Forensic Document Examination

5

Example 3: There are no writing impressions from page 2 of a medical record observed 

on the subsequent pages. 

Example 4: A screening was conducted between the submitted known samples of 100 

writers and the questioned document. It was determined that the writing from person A, 

B, and C best warranted a full evaluative comparison with the questioned document. This 

does not mean, at this stage, that the other 97 writers are excluded.
OSAC 2022-S-0034 Standard for the Expression of

Conclusions in Forensic Document Examination

6

Annex A (informative) Bibliography

1) Martire	KA,	Kemp	RI,	Watkins	I,	Sayle	MA,	Newell	BR.	The	expression	and	

interpretation	of	uncertain	forensic	science	evidence:	verbal	equivalence,	evidence	

strength,	and	the	weak evidence	effect.	Law	Hum	Behav.	2013	Jun;37(3):197-207.	doi:	

10.1037/lhb0000027.	PMID:	23750600.

2) “ENFSI	Guideline	for	Evaluative	Reporting	in	Forensic	Science,”	published	March	2015,	

http://enfsi.eu/wp-content/uploads/2016/09/m1_guideline.pdf

3) National	Institute	of	Forensic	Sciences	Australia-New	Zealand,	“An	Introductory	Guide	

to	Evaluative	Reporting,”	June	2017,	http://www.anzpaa.org.au/forensic-science/ourwork/projects/evaluative-reporting)