Distinguishing Characteristics of Robotic Writing

Advances in robotic handwriting technology create new challenges for forensic document examiners. In the past, devices such as the autopen were used to replicate signatures of government officials and corporate companies. In today's technology, companies such as Bond utilize robots to create written documents, which mimic natural patterns of handwriting. They generate customizable written samples by simulating pen movements and letter formations. Four forensic document examiners were given various reproduced questioned documents and utilized a modified ACE‐V (analysis, comparison, evaluation, verification) methodology to determine their genuineness. Examiners were able to make a distinction between the human writing samples and the skilled robotic equivalents. Several distinct features that are not seen in natural handwriting, such as even pen pressure and the superimposition of letterforms were observed in the robotic samples. Careful examination of identifying features of the Bond produced documents resulted in an opinion of nongenuineness.     

A preliminary investigation into handwriting examination by multiple measurements of letters and spacing

Theoretically, the scientific measurement of letters, letter spacing and word spacing provides a mathematical basis for the statistical comparison of handwriting. Ten volunteers were asked to write the same short passage. Ten features were measured, up to 10 times each, to characterise each writer. Measurements of repeat handwriting 2 years later failed to identify the writer, and this was attributed to a change in the height of the middle zone. Measurements of 'it' and 'th' spacings were the least affected.     

On the discriminability of the handwriting of twins

As handwriting is influenced by physiology, training, and other behavioral factors, a study of the handwriting of twins can shed light on the individuality of handwriting. This paper describes the methodology and results of such a study where handwriting samples of twins were compared by an automatic handwriting verification system. The results complement that of a previous study where a diverse population was used. The present study involves samples of 206 pairs of twins, where each sample consisted of a page of handwriting. The verification task was to determine whether two half-page documents (where the original samples were divided into upper and lower halves) were written by the same individual. For twins there were 1236 verification cases -- including 824 tests where the textual content of writing was different, and 412 tests where it was the same. An additional set of 1648 test cases were obtained from handwriting samples of nontwins (general population). To make the handwriting comparison, the system computed macro features (overall pictorial attributes), micro features (characteristics of individual letters), and style features (characteristics of whole-word shapes and letter pairs). Four testing scenarios were evaluated: twins and nontwins writing the same text and writing different texts. Results of the verification tests show that the handwriting of twins is less discriminable than that of nontwins: an overall error rate of 12.91% for twins and 3.7% for nontwins. Error rates with identical twins were higher than with fraternal twins. Error rates in all cases can be arbitrarily reduced by rejecting (not making a decision on) borderline cases. A level of confidence in the results obtained is given by the fact that system error rates are comparable to that of humans (lower than that of lay persons and higher than that of questioned document examiners [QDEs]).     

A comparative approach to the examination of Chinese handwriting Part 3—Disguise

Ninety-eight Chinese characters commonly encountered in casework were selected for the study and 437 sets of normal and disguised Chinese handwriting specimens were obtained. A survey of the disguised features revealed a more complicated pattern than disguised English handwriting in respect of the varieties of methods found. Over 30 methods of disguise were observed, of which only about half are comparable to English handwriting. The study confirms that disguise in Chinese handwriting is also simple and lacks originality. It is concluded that, similar to observations on disguised English writing, characteristics most often changed in disguised Chinese handwriting are those which most drastically affect the pictorial appearance of the writing and that other features altered are those which can conveniently be modified or substituted. The psychology of disguise is therefore postulated to be essentially the same in both (and probably all) language systems.     

卧姿笔迹特征的实验研究

目的为卧姿笔迹鉴定提供识别和评断的参考依据。方法比较108个不同书写水平者的仰卧、左侧卧、右侧卧及俯卧笔迹与正常坐姿笔迹特征上的异同点,通过大量实验数据的统计分析,总结出卧姿笔迹特征及其变化规律,探讨可能的变化原因,并分析卧姿笔迹检验的要点。结果卧姿笔迹在字体、写法、错别字、笔顺、字间组合和单字的基本搭配比例等特征上较稳定。这些特征可作为本质特征使用。4种卧姿中,俯卧笔迹特征最稳定;书写水平高者笔迹特征也较稳定。结论卧姿笔迹鉴定应结合卧姿笔迹特征变化规律,准确判断笔迹的形成条件,去伪存真,做出科学的评断。     

汉英文字笔迹特征的比较研究

目的更深入的了解不同国家、地区,不同文种,不同文化背景下的笔迹鉴定工作者对特定文字笔迹鉴定认识的差别。方法以中英文为例,对汉字和英文的特点和笔迹特征进行比较研究。结论汉英文字的笔迹特征分类体系大体相似,并无质的差别,但是不同文字的特点决定了其笔迹特征取向与侧重、价值评断、个别特征的使用率,以及对同一人笔迹特征多样变化的认识上还是有所区别,各具特色。     

Handwriting changes under the effect of alcohol

Document examiners are often faced with difficulties in evaluating handwriting by persons under the influence of alcohol. Although numerous articles are available on the subject of alcohol influence on handwriting quality, most of them were based on empirical data such as "few" or "increased", without any statistical evaluation. The aim of this research is to determine whether previous observations on reported effects of alcohol on handwriting are valid and to establish the predictability of observing specific effects. A total of 73 participants, who completed all steps of the experiment, were surveyed. Handwriting samples were taken before and after the consumption of alcohol. The test form, including criteria of prior studies used by document examiners, was evaluated with the help of a Olympus X-Tr stereo microscope, direct and oblique angle lighting and a video spectral comparator (VSC 2000). Measurements were done by means of digital caliper, statistics using repeated measures ANOVA, Pearson correlation, Pearson Chi square test, McNemar test and Wilcoxon signed rank test.The results revealed that the handwriting parameters such as word lengths, height of upper and lower case letters, height of ascending letter, height of descending letter, spacing between words, number of angularity, number of tremor, and number of tapered ends are all significantly increased under the effect of alcohol.It was also determined that the significant correlation between the alteration of handwriting parameters such as height of upper and lower case letters, number of angularity, number of tapered ends and the amount of alcohol. Furthermore, it does not confirm the conclusions of previous studies stating that alcohol levels are not proper indicators. Our data strongly confirms that handwriting changes can be observed at any level of alcohol.None of the alterations in handwriting can be attributed to the effects of alcohol intake alone. However, the presence of some alterations together is strongly suggestive that the person was under the influence of alcohol.First of all, the duty of handwriting examiner is to identify if the questioned and known sample are coming from the same source. Consequently, as this explanatory analysis suggests that differences between sober and intoxicated persons can be identified in handwriting, but the examiner's judgement must be proportionately cautious, keeping in mind the abnormally wide range of variation.     

A Set of Handwriting Features for Use in Automated Writer Identification,

A writer's biometric identity can be characterized through the distribution of physical feature measurements (“writer's profile”); a graph‐based system that facilitates the quantification of these features is described. To accomplish this quantification, handwriting is segmented into basic graphical forms (“graphemes”), which are “skeletonized” to yield the graphical topology of the handwritten segment. The graph‐based matching algorithm compares the graphemes first by their graphical topology and then by their geometric features. Graphs derived from known writers can be compared against graphs extracted from unknown writings. The process is computationally intensive and relies heavily upon statistical pattern recognition algorithms. This article focuses on the quantification of these physical features and the construction of the associated pattern recognition methods for using the features to discriminate among writers. The graph‐based system described in this article has been implemented in a highly accurate and approximately language‐independent biometric recognition system of writers of cursive documents.     

Identification of the Class Characteristics in the Handwriting of Polish People Writing in English

Abstract: An investigation was carried out to identify the class characteristics of Polish people writing in English and to specifically identify those characteristics that separate Polish handwriting from English handwriting. In the first stage, 40 Polish and 40 English handwriting samples were collected and systematically examined. In total, 31 features were identified that occurred in ≥25% of the Polish handwriting samples and therefore considered class characteristics. Of these, chi‐square analyses identified 21 class characteristics that occurred significantly more in Polish compared to English handwriting. Twenty‐one of the class characteristics in the Polish handwriting had similar constructions to the copybook pattern thus supporting the theory that class characteristics frequently stem from the taught writing system. In the second stage, an algorithm was developed using seventeen of the class characteristics that successfully discriminated between a further 13 Polish and 12 English handwriting samples.     

Competency for Chinese Handwriting and Signature Examination

Chinese characters had their root some 4000 years ago and, with the growth in population, are used by over 1.3 billion people worldwide today; it is inevitable that document examiners would encounter cases involving the examination of Chinese handwriting regardless of their location. Although there are extensive studies on the examination of English handwriting in the literature, similar studies on Chinese handwriting are relatively limited. We are seeking to explore the obstacles and challenges for a document examiner who is unfamiliar with Chinese characters to apply the principles of identification and elimination of authorship described in the literature to examine Chinese handwriting, and how can these document examiners demonstrate their competency for conducting Chinese handwriting examination. This study provides a review of the literature, compares the methodology and key features in English and Chinese handwriting examination, and describes various workshops and proficiency testing programs organized to assist document examiners seeking development in Chinese handwriting and signature examination.     

Detecting deception in second‐language speakers

Purpose. We examined whether language proficiency had an impact on lie detection. Methods. We collected video footage of 30 targets who spoke English as their native or second language and who lied or told the truth about a transgression. Undergraduate students (N = 51) then judged the veracity of these 30 clips and indicated how confident they were in their ratings. Results. Participants were more confident when judging native‐language truth‐tellers than second‐language truth‐tellers. In addition, participants were more likely to exhibit a truth‐bias when observing native‐language speakers, whereas they were more likely to exhibit a lie‐bias when viewing second‐language speakers. Conclusions. Given the difficulties and biases associated with second‐language lie detection, further research is needed.     

浅谈笔迹线条主动触觉在笔迹鉴定中的运用

笔迹是书写运动的轨迹,在观察静态特征的同时运用其动态特征,无疑可以提高笔迹鉴定的水平。但如何获取字迹的书写压力、书写速度和加速度等动态特征,目前还是个难题。笔迹心理学中笔迹线条主动触觉的分析是将笔迹书写时的压力与速度贯穿于字迹观察分析的始终,将其运用于笔迹鉴定,可在传统的笔迹鉴定二维平面字迹特征的视觉观察分析模式基础上,将视觉观察与触觉体验相结合,形成字迹形态二维平面特征与书写时笔向下的力度,和沿笔画书写的速度相结合的四维特征观察分析模式。     

笔迹动态特征研究

笔迹是通过书写运动形成的轨迹,由静态要素和动态要素所组成,承载着时间和空间信息。笔迹动态特征是客观存在的,它是书写人书写技能和书写习惯的外在表现,主要包括速度特征、笔力特征、脉冲特征、节奏特征等。对笔迹动态特征进行研究,多视域地挖掘和认识笔迹特征,可为笔迹检验鉴定意见提供更全面、更深层的支撑。     

The Influence of Lying Body Position on Handwriting

Although the problem of handwriting variability due to lying body position has practical significance, particularly for last will cases, it has not been sufficiently studied. The presented experiment aimed to recognize how such posture may influence handwriting features. Samples of text and signatures were collected from 50 healthy individuals, aged 23–58, produced in three postures: typical sitting position (SP) and two different lying positions (LP1 & LP2). Using the SP sample of each individual as a specimen, eleven characteristics in LP1 and LP2 samples were evaluated as similar or different. Nine other features were measured with a specialized software, and their conformity was tested with Student's t‐test. Although none of the characteristics differed significantly in most cases, variation occurred in pen pressure, margins, baselines, and heights of letters. Additionally, a series of blind tests revealed that lying position of the individuals did not hinder the possibility to identify their writings.     

Forensic examination of effects of Parkinsonism on various handwriting characteristics

Parkinsonism is a neurodegenerative syndrome that causes impairment of motor skills in affected persons. Thus, adverse effects may be produced in the handwriting of persons suffering from Parkinsonism. Medication used for the treatment of Parkinsonism is known to subside certain motor defects for specific time intervals, showing slight differences or improvement in certain handwriting characteristics during those intervals on the same day as compared to the ones executed before medication. Certain handwriting characteristics affected due to Parkinsonism may be mistaken as forged features due to poor line quality, which can cause suspicion upon the authenticity of important legal documents. The present research work has been carried out to determine the effects of Parkinsonism and medication used for its treatment on handwriting. Handwriting/signature samples executed before and after the onset of Parkinsonism (both pre- and post-medication) have been randomly collected from 70 participants. These handwritings have been evaluated separately and compared inter-se for various handwriting characteristics with qualitative and statistical approach. The results have demonstrated significant changes in most of the characteristics in both affected writings of majority of participants as compared to their corresponding earlier writings. Thus, forensic document experts should be aware of the detrimental effects of Parkinsonism on handwriting in pre- and post-medication conditions of this ailment.     

签名笔迹动态特征的理论研究

本文以签名笔迹为研究对象,提取书写过程中的动态特征,在此基础上,对签名笔迹动态特征的概念和属性进行了深入的探讨,构建了一套较为完整的签名笔迹动态特征的理论系统。     

Individuality of handwriting

Motivated by several rulings in United States courts concerning expert testimony in general, and handwriting testimony in particular, we undertook a study to objectively validate the hypothesis that handwriting is individual. Handwriting samples of 1,500 individuals, representative of the U.S. population with respect to gender, age, ethnic groups, etc., were obtained. Analyzing differences in handwriting was done by using computer algorithms for extracting features from scanned images of handwriting. Attributes characteristic of the handwriting were obtained, e.g., line separation, slant, character shapes, etc. These attributes, which are a subset of attributes used by forensic document examiners (FDEs), were used to quantitatively establish individuality by using machine learning approaches. Using global attributes of handwriting and very few characters in the writing, the ability to determine the writer with a high degree of confidence was established. The work is a step towards providing scientific support for admitting handwriting evidence in court. The mathematical approach and the resulting software also have the promise of aiding the FDE.     

低水平书写签名字迹的分析与鉴定

在文件检验工作中,少量字的签名字迹性质判断具有一定难度,若出现时间相隔久远,同期样本稀少,当事人年龄跨度几十年的案件,要对字迹性质作出准确判断将更困难。本文通过一起经济纠纷案,就三十年前低书写水平的签名字迹进行检材与样本分析、特征价值判断、背景调查、综合评断分析与经验总结,强调在检验中应当全面了解当事人的背景材料,对案件事实与鉴定要求之间的关联性进行深入调查研究,还需要准确把握字迹变化的原因,注意避免因书写习惯的变化性因素而错误评断字迹特征属性,进而做出科学、准确的鉴定意见。     

Using automated comparisons to quantify handwriting individuality

The proposition that writing profiles are unique is considered a key premise underlying forensic handwriting comparisons. An empirical study cannot validate this proposition because of the impossibility of observing sample documents written by every individual. The goal of this paper is to illustrate what can be stated about the individuality of writing profiles using a database of handwriting samples and an automated comparison procedure. In this paper, we provide a strategy for bounding the probability of observing two writers with indistinguishable writing profiles (regardless of the comparison methodology used) with a random match probability that can be estimated statistically. We illustrate computation of this bound using a convenience sample of documents and an automated comparison procedure based on Pearson's chi-squared statistic applied to frequency distributions of letter shapes extracted from handwriting samples. We also show how this bound can be used when designing an empirical study of individuality.