Giovanni Colavizza

Publications associées (29)

A digital reconstruction of the 1630–1631 large plague outbreak in Venice

Giovanni Colavizza, Frédéric Kaplan, Gianrocco Lazzari, Marcel Salathé

The plague, an infectious disease caused by the bacterium Yersinia pestis, is widely considered to be responsible for the most devastating and deadly pandemics in human history. Starting with the infamous Black Death, plague outbreaks are estimated to have killed around 100 million people over multiple centuries, with local mortality rates as high as 60%. However, detailed pictures of the disease dynamics of these outbreaks centuries ago remain scarce, mainly due to the lack of high-quality historical data in digital form. Here, we present an analysis of the 1630–1631 plague outbreak in the city of Venice, using newly collected daily death records. We identify the presence of a two-peak pattern, for which we present two possible explanations based on computational models of disease dynamics. Systematically digitized historical records like the ones presented here promise to enrich our understanding of historical phenomena of enduring importance. This work contributes to the recently renewed interdisciplinary foray into the epidemiological and societal impact of pre-modern epidemics.

2020

Chargement

Quantifying Engagement with Citations on Wikipedia

Giovanni Colavizza, Tiziano Piccardi, Robert West

Wikipedia is one of the most visited sites on the Web and a common source of information for many users. As an encyclopedia, Wikipedia was not conceived as a source of original information, but as a gateway to secondary sources: according to Wikipedia's guidelines, facts must be backed up by reliable sources that reflect the full spectrum of views on the topic. Although citations lie at the heart of Wikipedia, little is known about how users interact with them. To close this gap, we built client-side instrumentation for logging all interactions with links leading from English Wikipedia articles to cited references during one month, and conducted the first analysis of readers' interactions with citations. We find that overall engagement with citations is low: about one in 300 page views results in a reference click (0.29% overall; 0.56% on desktop; 0.13% on mobile). Matched observational studies of the factors associated with reference clicking reveal that clicks occur more frequently on shorter pages and on pages of lower quality, suggesting that references are consulted more commonly when Wikipedia itself does not contain the information sought by the user. Moreover, we observe that recent content, open access sources, and references about life events (births, deaths, marriages, etc.) are particularly popular. Taken together, our findings deepen our understanding of Wikipedia's role in a global information economy where reliability is ever less certain, and source attribution ever more vital.

ASSOC COMPUTING MACHINERY2020

Chargement

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Wikipedia is one of the most visited sites on the Web and a common source of information for many users. As an encyclopedia, Wikipedia was not conceived as a source of original information, but as a gateway to secondary sources: according to Wikipedia's guidelines, facts must be backed up by reliable sources that reflect the full spectrum of views on the topic. Although citations lie at the heart of Wikipedia, little is known about how users interact with them. To close this gap, we built client-side instrumentation for logging all interactions with links leading from English Wikipedia articles to cited references during one month, and conducted the first analysis of readers' interactions with citations. We find that overall engagement with citations is low: about one in 300 page views results in a reference click (0,29% overall; 0,56% on desktop; 0,13% on mobile). Matched observational studies of the factors associated with reference clicking reveal that clicks occur more frequently on shorter pages and on pages of lower quality, suggesting that references are consulted more commonly when Wikipedia itself does not contain the information sought by the user. Moreover, we observe that recent content, open access sources, and references about life events (births, deaths, marriages, etc.) are particularly popular. Taken together, our findings deepen our understanding of Wikipedia's role in a global information economy where reliability is ever less certain, and source attribution ever more vital.

RUSSIAN NATL PUBLIC LIBRARY SCIENCE & TECHNOLOGY2020

Chargement

Index-Driven Digitization and Indexation of Historical Archives

Giovanni Colavizza, Maud Ehrmann

The promise of digitization of historical archives lies in their indexation at the level of contents. Unfortunately, this kind of indexation does not scale, if done manually. In this article we present a method to bootstrap the deployment of a content-based information system for digitized historical archives, relying on historical indexing tools. Commonly prepared to search within homogeneous records when the archive was still current, such indexes were as widespread as they were disconnected, that is to say situated in the very records they were meant to index. We first present a conceptual model to describe and manipulate historical indexing tools. We then introduce a methodological framework for their use in order to guide digitization campaigns and index digitized historical records. Finally, we exemplify the approach with a case study on the indexation system of the X Savi alle Decime in Rialto, a Venetian magistracy in charge for the exaction—and related record keeping—of a tax on real estate in early modern Venice.

2019

Chargement

Linked Books: un indice citazionale per la storia di Venezia

Giovanni Colavizza, Matteo Romanello

We present the outcomes of the Linked Books project, resulting in a prototype citation index interlinking the Italian national library catalog (Opac SBN) with the information system of the State Archive of Venice and international authority records or “metaengines” such as VIAF.org and Europeana. Our prototype includes 3.850.581 citations extracted from a corpus of 2.475 volumes, of which 1.905 monographs, and 552 journal volumes, or 5.496 articles therein. The corpus is focused on the history of Venice. The Linked Books project allowed us to explore the feasibility and desirability of a citation index for the humanities, and to face and solve technical challenges including: the selection of a thematically representative corpus from bibliographic resources and expertise, the digitization of these materials within the bounds of copyright, the automatic extraction of citations and the development of public search interfaces.

2019

Chargement

Historical newspapers are of interest to many humanities scholars as sources of information and language closely tied to a particular time, social context and place. Digitised newspapers are also of interest to many data-driven researchers who seek large bodies of text on which they can try new methods and tools. Recently, large consortia projects applying data science and computational methods to historical newspapers at scale have emerged, including NewsEye, \textit{impresso}, Oceanic Exchanges and Living with Machines. This multi-paper panel draws on the work of a range of interdisciplinary newspaper-based digital humanities and/or data science projects, alongside 'provocations' from two senior scholars who will provide context for current ambitions. As a unique opportunity for stakeholders to engage in dialogue, for the DH2019 community to ask their own questions of newspaper-based projects, and for researchers to map methodological similarities between projects, it aims to have a significant impact on the field.

2019

Chargement

Characterizing in-text citations in scientific articles: A large-scale analysis

Giovanni Colavizza

We report characteristics of in-text citations in over five million full text articles from two large databases – the PubMed Central Open Access subset and Elsevier journals – as functions of time, textual progression, and scientific field. The purpose of this study is to understand the characteristics of in-text citations in a detailed way prior to pursuing other studies focused on answering more substantive research questions. As such, we have analyzed in-text citations in several ways and report many findings here. Perhaps most significantly, we find that there are large field-level differences that are reflected in position within the text, citation interval (or reference age), and citation counts of references. In general, the fields of Biomedical and Health Sciences, Life and Earth Sciences, and Physical Sciences and Engineering have similar reference distributions, although they vary in their specifics. The two remaining fields, Mathematics and Computer Science and Social Science and Humanities, have different reference distributions from the other three fields and between themselves. We also show that in all fields the numbers of sentences, references, and in-text mentions per article have increased over time, and that there are field-level and temporal differences in the numbers of in-text mentions per reference. A final finding is that references mentioned only once tend to be much more highly cited than those mentioned multiple times.

2018

Chargement

Printing materials and technologies in the 15th−17th century book production: an undervalued research field

Fauzia Albertin, Giovanni Colavizza

We present a systematic non-invasive investigation of a large corpus of early printed books, exploiting multiple techniques. This work is part of a broader project -- Argeia -- aiming to study early printing technologies, their evolution and, potentially, the identification of physical/chemical fingerprints of different manufactures and/or printing dates. We analyzed sixty volumes, part of the important collection of the Ateneo Veneto in Venice (Italy), printed between the 15th and the 17th centuries in the main European manufacturing centers. We present here the results of the imaging analysis of the entire corpus and the X-Ray Fluorescence (XRF) investigation performed, focusing on the XRF data and their statistical treatment using a combination of Principal Component Analysis (PCA) and Logistic Regression. Thanks to the broad XRF investigation -- more than 200 data points -- and to the multidisciplinary approach, we were able to discriminate the provenances of the paper -- in particular for the German and Venetian volumes -- and we potentially identified a chemical fingerprint of Venetian papers.

Elsevier2018

Chargement

The Closer the Better: Similarity of Publication Pairs at Different Co-Citation Levels

Giovanni Colavizza

We investigate the similarities of pairs of articles which are co-cited at the different co- citation levels of the journal, article, section, paragraph, sentence and bracket. Our results indicate that textual similarity, intellectual overlap (shared references), author overlap (shared authors), proximity in publication time all rise monotonically as the co-citation level gets lower (from journal to bracket). While the main gain in similarity happens when moving from journal to article co-citation, all level changes entail an increase in similarity, especially section to paragraph and paragraph to sentence/bracket levels. We compare results from four journals over the years 2010-2015: Cell, the European Journal of Operational Research, Physics Letters B and Research Policy, with consistent general outcomes and some interesting differences. Our findings motivate the use of granular co-citation information as defined by meaningful units of text, with implications for, among others, the elaboration of maps of science and the retrieval of scholarly literature.

2018

Chargement

The Closer the Better: Similarity of Publication Pairs at Different Cocitation Levels

Giovanni Colavizza

2018

Chargement