Universitat Pompeu Fabra
Institut Universitari de Lingüística Aplicada
 
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ForensicLab / Expert witness

PLAGIARISM DETECTION

Plagiarism involves intentional lifting of an idea and/or intentional copying of the text (linguistic, musical, etc.) used to express that idea, to cover up non-originality. So it seems that sometimes it is the idea, sometimes it is the language, sometimes it is both that are at stake; in other words, that both form and content are relevant issues to its definition.

In cases of plagiarism forensic linguists are called in to help a Court decide whether two or more texts have been produced independently or have been copied from an original text.

ForensicLab at IULA has specialised in the detection of plagiarism in two specific areas:

The protocol used involves the following activities:

The use of quantitative linguistic evidence can assist the analyst in cases of plagiarism and add both internal and external validity to the investigation. In order to determine the existence of plagiarism we use the latest version of CopyCatch, called CopyCatch Gold, designed by David Woolls from CFL Software Development. This tool handles multiple document types and allows rapid processing of the data in order to identify textual similarity. The output is enhanced to show both phrase and sentence matches and any text pair can be marked up to show the way in which the shared vocabulary appears in the text.  The use of quantitative linguistic evidence (VARBRUL 2 y 3; GOLDVARB 2001) can help the analyst in ensuring internal and external validity in their investigation and in consultancy.

Measurements

AUTHORSHIP ATTRIBUTION

In cases of authorship determination/attribution,  forensic linguists are called in to help a Court decide among several candidates whether the author of a particular set of texts is also the author of another set of texts (authorship determinations) , o whether one can attribute the authorship of a specific text (for example, a suicide note, or extortion letters) to a particular author (authorship attribution).

ForensicLab at IULA specialises in two specific areas of authorship analysis:

The protocol used involves the following tasks:

In order to determine and attribute authorship ForensicLab uses reference corpora to establish the rarity/expectancy of "linguistics markers" and marked and salient variables by means of applying multivariate analysis (Varbrul 2 and 3; Goldvarb2001). Depending on the nature of the case (amount of data, simple size, etc.), our laboratory can also use other statistical techniques to establish that sets of disputed ad non-disputed texts have been written by the same author. At present, ForensicLab is developing an automatic tool and technique of forensic authorship analysis that has been tested in real and non real cases.

SPEAKER IDENTIFICATION

In cases of speaker identification forensic linguists are called in to help a Court determine the authorship of a disputed voice.

The Forensic Linguistics Lab at IULA specialises in two specific areas:

Voice-Speaker verification and Speaker identification involve a joint analysis of voices from an auditive and acoustic point of view. Auditive analysis does not use any equipment for speaker identification and is rather based on the researcher's experience and expertise.  Acoustic analysis, on the other hand, is based upon the analysis of the acoustic properties of speech by means of speech technology (spectrogram,  voice multidimensional analysis, fundamental frequency, cochleagrams, LTAS, etc.) and statistical analysis techniques.

When we listen somebody speak, the listener draws information on the content (what is being said) and the person speaking (voice quality). According to Rose (2002), voice quality has two components: the organic component and the articulatory component (o articulatory adjustment). The former refers to the properties of sound which are determined by the speaker's physiology (form and volume of the vocal cavity, the specific characteristics of the vocal cords, etc.) and the latter refers to the position and adjustment of the articulatory organs (tongue, lips, etc.).

For forensic analysis of speaker identification all components are important: in voice quality, the organic component is determined by the physiological characteristics, and the articulatory components by his/her idiosyncratic articulatory habits. Phonetic quality is determined by dialect, sociolect, accent, verbal habits, etc.

The protocol used in our laboratory involves the following tasks:

In order to undertake acoustic analysis, the Forensic Linguistics Laboratory uses the latest versions of the most reputable programmes of acoustic analysis and voice edition, as well as specific applications developed in our laboratory to engage in comparative analysis. The acoustic data obtained are treated statistically.

LINGUISTIC PROFILING

In cases of linguistic profiling forensic linguists are called in to help in the construction of a suspect's profile. Drawing from the linguistic analysis of the voice, one can establish the author's geographical and social origin, gender, age, weight, height, usual language, language contact, etc. 

ForensicLab specialises in linguistic profiling in Catalan, Spanish and English.

Linguistic profiling involves auditive and acoustic analysis of unknown speakers' recordings in order to determine several traits or characteristics that can be inferred from the voice: origin, sociolect, gender and age, possible pathologies, weight and height, usual language, language contact, etc.

The protocol used in our laboratory involves the following tasks:

In order to undertake acoustic analysis, the Forensic Linguistics Laboratory uses the latest versions of the most reputable programmes of acoustic analysis and voice edition, as well as specific applications developed in our laboratory to engage in comparative analysis. The acoustic data obtained are treated statistically.

TRANSCRIPTION AND AUTHENTIFICATION OF RECORDINGS

In cases of authentification of recordings, forensic linguists are called in to clean out recordings from undesirable noise and also to transcribe the recorded content. In cases where the authenticity of a recording is questioned, Forensiclab has at its disposal several tools to determine if such recording has been manipulated.

TRADEMARKS, PATENTS AND FOOD LABELLING

In cases of trademark and patent litigation, forensic linguists are called in to make a linguistic analysis of patents and to characterise trademarks by their appearance (orthography, colour, typology and design), phonologically for sound and semantically for meaning, in order to establish whether falsification has occurred and confusion has been created. In food labelling, forensic linguists can make proposals of new wordings for ambiguous labels, which can cause a situation in which the consumer fails to follow the guidelines provided.

FORENSIC LINGUISTIC MEDIATION

On other occasions, forensic linguists are called in to analyse the possible text ambiguity or text alteration in officialised or private contexts or in legal, court and police written/spoken discourse, involving either the administration or the users themselves. In all these cases, forensic linguists analyse the texts and mediate between parties.

RECENT CONSULTANCY CASES

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