Justified Group Belief, Group Knowledge and Being in a Position to Know

Episteme ◽  
2020 ◽  
pp. 1-8
Author(s):  
Jakob Koscholke
Keyword(s):  
Sufficient Conditions ◽  
Single Group ◽  
Group Knowledge ◽  
Group Belief ◽  
Group Member

Abstract Jennifer Lackey has recently presented a new and lucid analysis of the notion of justified group belief, i.e. a set of individually necessary and jointly sufficient conditions for a group to justifiedly believe some proposition. In this paper, however, I argue that the analysans she proposes is too narrow: one of the conditions she takes to be necessary for justified group belief is not necessary. To substantiate this claim, I present a potential counterexample to Lackey's analysis where a group knows and thus justifiedly believes some proposition but there is no single group member who actually believes that proposition. I close by defending the example against the objection that the group in question does not know but is at most in a position to know the target proposition.

Group belief

2020 ◽  
Author(s):  
Thomas Ågotnes ◽  
Yì N Wáng
Keyword(s):  
Modal Logic ◽  
Common Belief ◽  
Distributed Knowledge ◽  
Common Assumption ◽  
Group Knowledge ◽  
Group Belief ◽  
The Common ◽  
Negative Introspection

Abstract While logical formalizations of group notions of knowledge such as common and distributed knowledge have received considerable attention in the literature, most approaches being based on modal logic, group notions of belief have received much less attention. In this paper we systematically study standard notions of group belief under different assumptions about the properties of belief. In particular, we map out (lack of) preservation of belief properties against different standard definitions of group belief. It turns out that what is called group belief most often is not actually belief, i.e. does not have the properties of belief. In fact, even what is called group knowledge is sometimes not actually knowledge either. For example, under the common assumption that belief has the KD45 properties, neither common belief (does not satisfy the negative introspection axiom 5) nor distributed belief (does not satisfy the consistency axiom D) are not actually belief. There has been some confusion in the literature regarding soundness of proposed axiomatizations of logics with distributed knowledge, related to the mentioned lack of preservation. In this paper we also present detailed completeness proofs of sound and complete axiomatizations of KD45 with distributed belief, both with and without common belief.

Introduction

2020 ◽  
pp. 1-18
Author(s):  
Jennifer Lackey
Keyword(s):  
Collective Responsibility ◽  
The Other ◽  
Collective Actions ◽  
Making Sense ◽  
Group Knowledge ◽  
Knowledge Group ◽  
Group Belief ◽  
The One ◽  
Collective Epistemology ◽  
Shed Light

In this Introduction, a central debate in the literature on the epistemology of groups is discussed. On the one hand, deflationary theorists hold that group phenomena, such as group beliefs, can be understood entirely in terms of individual members and their states. On the other hand, inflationary theorists, maintain that group phenomena are importantly over and above, or otherwise distinct from, individual members and their states. It is argued that settling some of the issues in this debate lies at the heart of making sense of collective responsibility. It is also emphasized that a central aim of this book is to make progress in understanding crucial notions in collective epistemology—group belief, justified group belief, group knowledge, group assertion, and group lies—so as to shed light on whether it is groups, their individual members, or both who ought to be held responsible for collective actions. Finally, overviews of each chapter are provided.

Group Knowledge

2020 ◽  
pp. 111-137
Author(s):  
Jennifer Lackey
Keyword(s):  
Functional Role ◽  
Scientific Community ◽  
Social Knowledge ◽  
Single Individual ◽  
Collective Knowledge ◽  
Group Knowledge ◽  
Group Members ◽  
Group Belief

In this chapter, two influential kinds of purported group knowledge that pose challenges to my account of justified group belief are examined. The first is often referred to as “social knowledge,” a paradigmatic instance of which is the so-called knowledge possessed by the scientific community, where no single individual knows a proposition, but the information plays a functional role in the community. The second is “collective knowledge,” where knowledge may be imputed to a group by aggregating bits of information had by its individual members. It is shown that both social knowledge and collective knowledge sever the crucial connection between knowledge and action, and open the door to serious abuses, not only epistemically, but morally and legally as well. Bits of information that are merely accessible to group members, or individual instances of knowledge that are aggregated with no communication, do not amount to group knowledge in any robust sense.

Representations and Robustly Collective Attitudes

2018 ◽  
Author(s):  
Jeroen de Ridder
Keyword(s):  
Distributed Cognition ◽  
Extended Mind ◽  
Controversial Issue ◽  
Cognitive States ◽  
Group Knowledge ◽  
Group Belief ◽  
Collective Representations ◽  
Collective Belief ◽  
Natural Way

One argument against the existence of robustly collective cognitive states such as group belief and group knowledge is that there are no collective representations, i.e., representations held by groups rather than individuals. Since belief requires representation, so the argument goes, there can be no collective belief. This chapter replies to that argument. First, the chapter scrutinizes the assumption that belief requires representation and points out that it is in fact a substantive and controversial issue whether belief indeed requires representation and, if it does, how so. Secondly, the chapter argues that even if we grant the above assumption, the argument can be resisted, since there is a natural way to make sense of collective representations. By drawing on the ideas of the extended mind and distributed cognition hypotheses, this chapter outlines how we can conceive of collective representations and thereby undermine the argument against group cognitive states.

Perspective Sharing in Culture Group Games

2021 ◽  
Vol 5 (CHI PLAY) ◽  
pp. 1-24
Author(s):  
Maria Vayanou ◽  
Akrivi Katifori ◽  
Yannis Ioannidis
Keyword(s):  
User Study ◽  
Single Group ◽  
Face To Face ◽  
Museum Visitors ◽  
Leading Role ◽  
The Social ◽  
Mobile Design ◽  
Mediator Role ◽  
Group Member

This work investigates how to digitally mediate perspective sharing and face-to-face conversations within groups of museum visitors. We use the case of a storytelling group game and explore the potential of mobile technology as a tool to facilitate perspective sharing activities. Using information asymmetry, a "Social Mediator" role is introduced: players' choices get displayed only to a single group member, who thus undertakes a leading role. The findings of an experience prototyping user study with playtesting in situ show that participants effectively and naturally carried out the pertinent dialogue facilitation activities. We identify behavioral patterns and discuss the insights they offer, showcasing how they shaped the mobile design for the particular use-case. We conclude that the distribution of the Social Mediator role between participants could successfully facilitate perspective sharing within groups and reflect on its potential and limitations in different collocated game experiences.

Some Contributions to the Theory of Near-Critical Bisexual Branching Processes

2007 ◽  
Vol 44 (02) ◽  
pp. 492-505
Author(s):  
M. Molina ◽  
M. Mota ◽  
A. Ramos
Keyword(s):  
Branching Process ◽  
Branching Processes ◽  
Sufficient Conditions ◽  
Positive Probability ◽  
Limit Laws ◽  
Bisexual Branching Processes ◽  
Probabilistic Evolution

We investigate the probabilistic evolution of a near-critical bisexual branching process with mating depending on the number of couples in the population. We determine sufficient conditions which guarantee either the almost sure extinction of such a process or its survival with positive probability. We also establish some limiting results concerning the sequences of couples, females, and males, suitably normalized. In particular, gamma, normal, and degenerate distributions are proved to be limit laws. The results also hold for bisexual Bienaymé–Galton–Watson processes, and can be adapted to other classes of near-critical bisexual branching processes.

The extinction time of a general birth and death process with catastrophes

1986 ◽  
Vol 23 (04) ◽  
pp. 851-858 ◽  
Author(s):  
P. J. Brockwell
Keyword(s):  
Laplace Transform ◽  
Size Distribution ◽  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Death Process ◽  
Extinction Time ◽  
Birth And Death Process ◽  
Different Types ◽  
The Laplace Transform ◽  
Necessary And Sufficient

The Laplace transform of the extinction time is determined for a general birth and death process with arbitrary catastrophe rate and catastrophe size distribution. It is assumed only that the birth rates satisfyλ0= 0,λj> 0 for eachj> 0, and. Necessary and sufficient conditions for certain extinction of the population are derived. The results are applied to the linear birth and death process (λj=jλ, µj=jμ) with catastrophes of several different types.

Normal approximations to discrete unimodal distributions

1986 ◽  
Vol 23 (04) ◽  
pp. 1013-1018
Author(s):  
B. G. Quinn ◽  
H. L. MacGillivray
Keyword(s):  
Stationary Distribution ◽  
Sufficient Conditions ◽  
Random Variables ◽  
Hypergeometric Distribution ◽  
Death Process ◽  
Normal Approximations ◽  
Discrete Random Variables ◽  
Birth Death

Sufficient conditions are presented for the limiting normality of sequences of discrete random variables possessing unimodal distributions. The conditions are applied to obtain normal approximations directly for the hypergeometric distribution and the stationary distribution of a special birth-death process.

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