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Quetelet Seminar: Invisibilities and Uncertainties in Population Sciences

Oct 27 2021 - Oct 29 2021

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Although information on individuals has never been so abundant, particularly through administrative databases (registers, censuses, surveys) or private databases (tracking of individuals on the internet or by telephone networks), many populations are partially, or sometimes completely, unaffected by observations and measurements, whether voluntarily or not. A distinction should be made between invisibility and statistical uncertainty. Invisibility concerns categories of persons and/or events that are not or no longer measured or are differently measured. Statistical uncertainty is the lack or absence of data concerning marginal populations and events are those that are rare and difficult to enumerate quantitatively. These different situations lead de facto to invisibility or statistical uncertainty.

Invisibility often stems from the absence or loss of legal and administrative recognition. It can be both the consequence, and conversely, the driving force behind a process of social exclusion and involuntary marginalisation. This is the case, for example, of the homeless, and of people in an irregular situation regarding territory. Invisibility can also be the result of a voluntary choice by those who fear being stigmatised or who wish to be on the margins of society in order to escape certain lifestyles, or avoid information being collected about them that they consider intrusive. These invisibilities, whether suffered or deliberately maintained, constitute forms of ruptures between the individual and society, through lack of consideration or recognition, through mistrust, or because of a void that the administrative apparatus is unable to fill.

Invisibility can also arise coincidentally, without necessarily reflecting marginalization. For example, the usual place of residence does not always correspond to the "legal" place of residence. This is particularly the case for students or workers who live in one place (alone, as a couple, in a shared flat, etc.) while remaining legally domiciled and registered in another (at their parents’, for instance). This generates a difficult census/observation of these individuals and/or double counting. This statistical invisibility may also concern certain lifestyles, at first out of the norm, but more frequent in a context of changing family and conjugal life courses. These examples are indicative of the growing diversity of lifestyles and their rapid evolution (same-sex partners, single parental adoptions, non-marital cohabitation, shared residence of children following a parental separation, etc.). They arouse the interest of social science researchers, but require constant adaptation of the data collection tools to efficiently consider "new" phenomena and new population categories.

At the same time, situations associated with past and/or present taboos are often subject to significant statistical underestimations. For example, questions about gender identities and sexual orientations remain minimal in the statistical space. Confronted with the heteronormativity of current statistics and of the whole society, lesbian, gay, bisexual, queer or transgender populations are likely to conceal their family or personal situation to escape social stigma, or because individuals do not recognize themselves in the proposed statistical categories. Administrative and statistical sources may elude some other sensitive topics because of the social and emotional weight they carry. Sexual and domestic violence is one example. Fear of reprisals, judgements and incomprehension are all arguments that may hold some victims back from reporting assaults or daily abuse. Finally, the social, religious and cultural history of a society leaves its mark on current reluctance to discuss delicate subjects, such as suicide, euthanasia or abortion. Because they trigger social condemnation and virulent debate, those topics are particularly difficult to study and to grasp without some form of bias or underestimation in traditional statistics, including in specific surveys on the subject.

The 2020 Quetelet Seminar proposes to examine not only these invisible populations and the uncertainty of events, but also the shortcomings of observation tools and how to statistically apprehend them. It seeks a better understanding of the determinants and effects of the process of statistical invisibility. Finally, it aims at highlighting the limits of current statistics in a context of multiple changes in our modern society.


  • Inscription fees: €150
  • NGOs/associations fees: €50
  • PhD/Student/retired registration fees: €20
  • Limited support will be available for authors from low-income countries.
  • The conference languages are English and French. However, all slides are requested to be in English even if the oral presentation is in French.
  • Conference venue: Louvain House, Traverse Comte Yves du Monceau, 1348 Louvain-la-Neuve
  • Submission website: easychair
  • Contact : chairequetelet [at]


Université Catholique de Louvain
Louvain-la-Neuve, Belgium