The use of the likelihood ratio for evaluative and investigative purposes in comparative forensic handwriting examination

This paper extends previous research and discussion on the use of multivariate continuous data, which are about to become more prevalent in forensic science. As an illustrative example, attention is drawn here on the area of comparative handwriting examinations. Multivariate continuous data can be obtained in this field by analysing the contour shape of loop characters through Fourier analysis. This methodology, based on existing research in this area, allows one describe in detail the morphology of character contours throughout a set of variables. This paper uses data collected from female and male writers to conduct a comparative analysis of likelihood ratio based evidence assessment procedures in both, evaluative and investigative proceedings. While the use of likelihood ratios in the former situation is now rather well established (typically, in order to discriminate between propositions of authorship of a given individual versus another, unknown individual), focus on the investigative setting still remains rather beyond considerations in practice. This paper seeks to highlight that investigative settings, too, can represent an area of application for which the likelihood ratio can offer a logical support. As an example, the inference of gender of the writer of an incriminated handwritten text is forwarded, analysed and discussed in this paper. The more general viewpoint according to which likelihood ratio analyses can be helpful for investigative proceedings is supported here through various simulations. These offer a characterisation of the robustness of the proposed likelihood ratio methodology.

Effects of Different Postural Conditions on Handwriting Variability

During their career, forensic document examiners will inevitably be confronted with handwriting carried out under unusual conditions (UnC). A questioned document signed on top of a car or on a vertical surface like a wall are two examples. These atypical circumstances may give rise to more variability of the signatures or written words, in particular if the body was in non-traditional writing position without the traditional support. Few studies were devoted to handwriting variability under unusual writing conditions. The current study investigates whether individual variability changes with special writing conditions. In a previous study (Sciacca & al, 2009), we found that eight repetitions were sufficient to obtain a correct estimation of the variance. In the present study, twelve subjects were asked to write two word sets eight times in upper and eight times in lower case, under different conditions : sitting and writing on a horizontal (usual condition UC) or vertical support; and standing, kneeling or laying while writing on a horizontal or vertical support (unusual conditions UnC). Words were written on a pen tablet, normalized in space and time and then averaged. The variance of the eight words was measured under all conditions. Results showed only an increase in variability under the laying and kneeling / vertical UnC. Within the five other postural conditions tested, handwriting was shown to be very stable.

Quantitative Assessment of Handwriting Evidence: The Value of the Shape of the Letter "A"

To provide a quantitative support to the handwriting evidence evaluation, a new method was developed through the computation of a likelihood ratio based on a Bayesian approach. In the present paper, the methodology is briefly described and applied to data collected within a simulated case of a threatening letter. Fourier descriptors are used to characterise the shape of loops of handwritten characters "a" of the true writer of the threatening letter, and: 1) with reference characters "a" of the true writer of the threatening letter, and then 2) with characters "a" of a writer who did not write the threatening letter. The findings support that the probabilistic methodology correctly supports either the hypothesis of authorship or the alternative hypothesis. Further developments will enable the handwriting examiner to use this methodology as a helpful assistance to assess the strength of evidence in handwriting casework.

Bayes factor for investigative assessment of selected handwriting features

This paper extends previous research [1] on the use of multivariate continuous data in comparative handwriting examinations, notably for gender classification. A database has been constructed by analyzing the contour shape of loop characters of type a and d by means of Fourier analysis, which allows characters to be described in a global way by a set of variables (e.g., Fourier descriptors). Sample handwritings were collected from right- and left-handed female and male writers. The results reported in this paper provide further arguments in support of the view that investigative settings in forensic science represent an area of application for which the Bayesian approach offers a logical framework. In particular, the Bayes factor is computed for settings that focus on inference of gender and handedness of the author of an incriminated handwritten text. An emphasis is placed on comparing the efficiency for investigative purposes of characters a and d.

Efficacy Of An Explicit Handwriting Program

The aim of this study was to investigate the effects of an explicit handwriting program introduced during the first grade of elementary school. Grade 1 children (N=23) with an age range of 6.1 to 7.4 yr. (15 girls, 8 boys) were administered an additional handwriting program of two weekly sessions of 45 min. over six weeks. Another group of 19 Grade 1 children (11 girls, 8 boys) received only the regular handwriting program of one weekly session. The Concise Assessment Scale for Children's Handwriting was administered to measure the changes in quality and speed of handwriting. The children given the explicit program showed better quality and speed of handwriting than did the control group. Their handwriting was more regular, with fewer ambiguous letters and fewer incorrect relative heights.

The "handwriting brain": a meta-analysis of neuroimaging studies of motor versus orthographic processes.

INTRODUCTION: Handwriting is a modality of language production whose cerebral substrates remain poorly known although the existence of specific regions is postulated. The description of brain damaged patients with agraphia and, more recently, several neuroimaging studies suggest the involvement of different brain regions. However, results vary with the methodological choices made and may not always discriminate between "writing-specific" and motor or linguistic processes shared with other abilities. METHODS: We used the "Activation Likelihood Estimate" (ALE) meta-analytical method to identify the cerebral network of areas commonly activated during handwriting in 18 neuroimaging studies published in the literature. Included contrasts were also classified according to the control tasks used, whether non-specific motor/output-control or linguistic/input-control. These data were included in two secondary meta-analyses in order to reveal the functional role of the different areas of this network. RESULTS: An extensive, mainly left-hemisphere network of 12 cortical and sub-cortical areas was obtained; three of which were considered as primarily writing-specific (left superior frontal sulcus/middle frontal gyrus area, left intraparietal sulcus/superior parietal area, right cerebellum) while others related rather to non-specific motor (primary motor and sensorimotor cortex, supplementary motor area, thalamus and putamen) or linguistic processes (ventral premotor cortex, posterior/inferior temporal cortex). CONCLUSIONS: This meta-analysis provides a description of the cerebral network of handwriting as revealed by various types of neuroimaging experiments and confirms the crucial involvement of the left frontal and superior parietal regions. These findings provide new insights into cognitive processes involved in handwriting and their cerebral substrates.

Handwriting and pre-frailty in the Lausanne cohort 65+ (Lc65+) study

BACKGROUND: Frailty is detected by weight loss, weakness, slow walking velocity, reduced physical activity or poor endurance/exhaustion. Handwriting has not been examined in the context of frailty, despite its functional importance. OBJECTIVE: Our goal was to examine quantitative handwriting measures in people meeting 0, 1, and 2 or more (2+) frailty criteria. We also examined if handwriting parameters were associated with gait performance, weakness, poor endurance/exhaustion and cognitive impairment. METHODS: From the population-based Lc65+, 72 subjects meeting 2+ frailty criteria with complete handwriting samples were identified. Gender-matched controls meeting 1 criterion or no criteria were identified. Cognitive impairment was defined by a Mini-Mental State Examination score of 25 or less or the lowest 20th percentile of Trail Making Test Part B. Handwriting was recorded using a writing tablet and measures of velocity, pauses, and pressure were extracted. RESULTS: Subjects with 2+ criteria were older, had more health problems and need for assistance but had higher education. No handwriting parameter differed between frailty groups (age and education adjusted). Writing velocity was not significantly slower among participants from the slowest 20th percentile of gait velocity but writing pressure was significantly lower among those from the lowest 20th percentile of grip strength. Poor endurance/exhaustion was not associated with handwriting measures. Low cognitive performance was related to longer pauses. CONCLUSIONS: Handwriting parameters might be associated with specific aspects of the frailty phenotype, but not reliably with global definitions of frailty at its earliest stages among subjects able to perform handwriting tests.

Handwriting Intervention: Impact on the Reading and Writing Abilities of High School Students

Handwriting is a functional task that is used to communicate thoughts using a written code. Research findings have indicated that handwriting is related to learning to read and learning to write. The purposes of this research project were to determine if a handwriting intervention would increase abilities in reading and writing skills, in graphomotor and visual-motor integration skills, and improve the participants’ self-perceptions and self-descriptions pertaining to handwriting enjoyment, competence, and effort. A single-subject research design was implemented with four struggling high school students who each received 10.5 to 15.5 hours of cursive handwriting intervention using the ez Write program. In summary, the findings indicated that the students showed significant improvements in aspects of reading and writing; that they improved significantly in their cursive writing abilities; and that their self-perceptions concerning their handwriting experience and competence improved. The contribution of handwriting to academic achievement and vocational success can no longer be neglected.

Note in Samuel Woodruff’s handwriting thanking the company for their offer

Note (1/2 page, handwritten) in Samuel Woodruff’s handwriting thanking the company for their offer. [This seems to be a rough note, with no salutation and no signature], n.d.

Letter to Jarvis, Conklin and Co. is in S.D. Woodruff’s handwriting, but unsigned regarding the Shelby and Cunningham accounts

Letter (1 ¼ pages, handwritten) to Jarvis, Conklin and Co. is in S.D. Woodruff’s handwriting, but unsigned regarding the Shelby and Cunningham accounts, March 25, 1883.

Syllable frequency effects in Spanish handwriting production. 'Efectos de la frecuencia silábica en la producción escrita del español'.

Resumen en español. Resumen basado en el de la publicación

First skills in numeracy 1. Handwriting book.

Ejercicios de aritmética para los alumnos de la etapa clave 1. Cuaderno de trabajo centrado en el cálculo y escrito específicamente para estimular en los niños el pensamiento matemático a través de una amplia gama de actividades. Su enfoque está basado en los objetivos del proyecto nacional de cálculo .

Nelson Phonics spelling and handwriting teacher's book.

Manual del profesor que proporciona una guía completa para la enseñanza de la escritura junto con un curso completo de fonética de la etapa clave 1 (Key Stage 1). Incluye una visión general sobre la mejor forma de vincular la escritura y el deletreo con la fonética. Proporciona orientación, lecciones y actividades para las competencias clave de la escritura y la ortografía con la secuencia fonética pasando de sonidos sencillos a sonidos más complejos a un ritmo y secuencia recomendada con las fichas elaboradas por el Department for Education and Skills (DfES).

The effect of the handwriting without tears program on student cursive writing achievement at Central Institute for the Deaf (CID)

Handwriting Without Tears (HWT) is a multi-sensory program that provides a simpler approach to the instruction of cursive handwriting. It was administered to a sample of third graders to assess the effectiveness of the program and determine if it would be a viable option for handwriting instruction at CID.