Shared structure need not be shared set-structure

Recent semantic approaches to scientific structuralism, aiming to make precise the concept of shared structure between models, formally frame a model as a type of set-structure. This framework is then used to provide a semantic account of (a) the structure of a scientific theory, (b) the applicability of a mathematical theory to a physical theory, and (c) the structural realist’s appeal to the structural continuity between successive physical theories. In this paper, I challenge the idea that, to be so used, the concept of a model and so the concept of shared structure between models must be formally framed within a single unified framework, set-theoretic or other. I first investigate the Bourbaki-inspired assumption that structures are types of set-structured systems and next consider the extent to which this problematic assumption underpins both Suppes’ and recent semantic views of the structure of a scientific theory. I then use this investigation to show that, when it comes to using the concept of shared structure, there is no need to agree with French that “without a formal framework for explicating this concept of ‘structure-similarity’ it remains vague, just as Giere’s concept of similarity between models does ...” (French, 2000, Synthese, 125, pp. 103–120, p. 114). Neither concept is vague; either can be made precise by appealing to the concept of a morphism, but it is the context (and not any set-theoretic type) that determines the appropriate kind of morphism. I make use of French’s (1999, From physics to philosophy (pp. 187–207). Cambridge: Cambridge University Press) own example from the development of quantum theory to show that, for both Weyl and Wigner’s programmes, it was the context of considering the ‘relevant symmetries’ that determined that the appropriate kind of morphism was the one that preserved the shared Lie-group structure of both the theoretical and phenomenological models. I wish to thank Katherine Brading, Anjan Chakravartty, Steven French, Martin Thomson-Jones, Antigone Nounou, Stathis Psillos, Dean Rickles, Mauricio Suarez and two anonymous referees for valuable comments and criticisms, and Gregory Janzen for editorial suggestions. Research for this paper was funded by a generous SSHRC grant for which I am grateful     

Analysing the perceptions of pedestrians and drivers to shared space

Shared space is an approach to improving streets and places where both pedestrians and vehicles are present, with layouts related more to the pedestrian scale and with features encouraging drivers to assume priority having been reduced or removed. It creates a more pedestrian-friendly environment than conventional street layouts, which are based on greater segregation between pedestrians and vehicles, while at the same time introducing uncertainty, which makes drivers engage more fully with their surroundings, leading to lower vehicle speeds and improved safety. This paper investigates the importance of certain person-, context- and design-specific factors affecting the perceptions of pedestrians and drivers to shared space. Using two web-based stated-preference surveys, two sets of responses are collected from pedestrians and drivers, who are presented with different combinations of binary factors forming scenarios. Regression analysis is carried out with logit models for each survey. The results suggest that pedestrians feel most comfortable in shared space under conditions which ensure their presence is clear to other road users – these conditions include low vehicular traffic, high pedestrian traffic, good lighting and pedestrian-only facilities. Conversely, the presence of many pedestrians and, in particular, children and elderly, makes drivers feel uneasy and, therefore, enhances their alertness.     

Human cognition, space, and the sedimentation of meaning

The goal of this paper is to explore, from a phenomenologically informed perspective, the phenomenon of the operative spatialization of human thinking, viewed in its relationship with the embodied human organism’s spatial experience. Operative spatialization in this context refers to the cognitive role and functioning of spatial schematizations and differentiations in human thinking. My particular focus is the domain of conceptualization. By drawing on Husserl’s discussion of the (linguistic) process of a sedimentation of meaning, I aim to show that spatialization functions in a structurally ambivalent manner. On the one hand, spatialization predisposes and thus narrows the scope of human conceptual thought. On the other hand, spatialization establishes an implicit cognitive scaffold indispensable for the development and practice of human higher-order thinking. The structure and functioning of this scaffold, I argue, is intrinsically related to the spatial structure and dynamics of human embodiment. Synthesizing insights from phenomenological studies concerning the experiential constitution of space, and classic and recent research findings from fields such as cognitive linguistics and psychology concerning the cognitive dimension of image-schemas and gestural behavior, I argue that the living human body functions centrally as the sense-constitutive ‘site of conversion’ (Husserl) between concrete structures of spatial experience and abstract structures of conceptual thought.     

Shared cognition as a product of, and precursor to, shared identity in negotiations

Three studies examined the hypothesis that shared cognition and group identification can be each other's catalysts as well as driving forces behind multiparty negotiation outcomes that might not otherwise be realized. Experiment 1 demonstrates that clear links exist between communication, the development of shared cognition and group identification, and integrative outcomes. The subsequent experiments isolated the causal directions of these links. Experiment 2 showed that stronger group identification before interaction was associated with the development of shared cognition in a subsequent phase of negotiation, which then increased the attainment of integrative outcomes. Conversely, a direct manipulation of shared cognition in Experiment 3 resulted in stronger identification during negotiation, which then led to more integrative outcomes. Thus, we find support for the theoretical claim that group identification can be both the product of, and precursor to, the development of shared cognition, with communication functioning as the interface between the two.     

Modeling pedestrian-cyclist interactions in shared space using inverse reinforcement learning

The objective of this study is to model the microscopic behaviour of mixed traffic (cyclist-pedestrian) interactions in non-motorized shared spaces. Video data were collected at two locations of Robson Square non-motorized shared space in downtown Vancouver, British Columbia. Trajectories of cyclists and pedestrians involved in interactions were extracted using computer vision algorithms. The extracted trajectories were used to obtain several variables that describe elements of road users’ behaviour including longitudinal and lateral distances, speed and speed differences, interaction angle, and cyclist acceleration and yaw rate. The road users behaviour was modeled as utility-based intelligent rational agents using the finite-state Markov Decision Process (MDP) framework with unknown reward functions. The study implemented Inverse Reinforcement Learning (IRL) using two algorithms: the Maximum Entropy (ME) algorithm, and the Feature Matching (FM) algorithm to recover/estimate the reward function weights of cyclists in two types of interactions with pedestrians: following and overtaking interactions. Reward function weights infer cyclist preferences during their interactions with pedestrians in non-motorized shared spaces, and can form the key component in developing agent based microsimulation model for road users. Furthermore, the estimated reward functions were used to estimate cyclists’ optimal policy for such interactions. A simulation platform was developed using the estimated reward functions and the cyclist optimal policies to simulate cyclist trajectories for the validation dataset. Results show that the Maximum Entropy (ME) IRL algorithm outperformed the Feature Matching (FM) IRL algorithm, and generally provided reasonable results for modeling such interactions in non-motorized shared spaces, considering the high degrees of freedom in movement and the more-complex road users interactions in such facilities. This research is considered an important step toward developing a full Agent-Based Model (ABM) for road users in shared space facilities to evaluate the safety and efficiency of such facilities.     

Shared leadership development and team performance: A new look at the dynamics of shared leadership

The present study offers new theoretical insights into the dynamics of shared leadership. Integrating arguments from shared leadership and team development theory, we examine how shared leadership changes over the course of a project team's life cycle and how this pattern of change relates to team performance. Guided by shared leadership theory and project team literature, we also explore team‐level factors, which may alter the pattern of shared leadership development. In particular, we propose that in project teams shared leadership develops in a nonuniform way, approximating an inverted U‐shaped pattern, increasing early in the team's life cycle, peaking around the midpoint, and then decreasing in the later phase. In turn, this development pattern relates positively to team performance. We also extend theory by explaining how specific team characteristics influence the pattern of shared leadership development. Using a three‐study approach, we empirically examine the hypothesized relationships and conclude with a general discussion of the theoretical and practical implications of our findings.     

Shared genes, shared experiences, and similarity of personality: data from 14,288 adult Finnish co-twins

Similarities for Extraversion (E) and Neuroticism (N) scale scores from the Eysenck Personality Inventory were evaluated in 7,144 adult twin pairs, drawn from the population-based Finnish Twin Cohort, as a function of the co-twins' genetic resemblance, gender, age, and the frequency of their social interaction with each other. To separate effects of shared genes from those of shared experience, we performed hierarchical multiple regressions of double-entry data matrices. Results establish the predictive significance of both genetic and experiential influences: Genetic effects remained significant when tested after the effects of social contact were first removed; conversely, for N scores, the effects of social contact remained significant when assessed after genetic influences were first removed. These findings establish genetic variance in major dimensions of adult personality but assign a significant role to common experience as well. The first finding constructively replicates reports by others; the second challenges the widespread assumption that shared experiences have a negligible impact on sibling similarity in adult personality.     

Literal meaning, conventional meaning and first meaning

Literal meaning is often identified with conventional meaning. In A Nice Derangement of Epitaphs Donald Davidson argues (1) that literal meaning is distinct from conventional meaning, and (2) that literal meaning is identical to what he calls first meaning. In this paper it is argued that Davidson has established (1) but not (2), that he has succeeded in showing that there is a distinction between literal meaning and conventional meaning but has failed to see that literal meaning and first meaning are also distinct. This failure is somewhat surprising, since it is through a consideration of Davidson's notion of radical interpretation that the distinction between literal meaning and first meaning becomes apparent.I am grateful to the Social Sciences and Humanities Research Council of Canada for its financial support, and to Mark Mercer, Tom Patton and Gary Wedeking for their helpful comments. I would also like to thank David Checkland, who discussed A Nice Derangement of Epitaphs with me at length some years ago.     

Behaviour and perceptions of powered two-wheeler users in street designs with elements of shared space

Inspired by developments in urban planning, the concept of “shared space” has recently emerged as a way of creating a better public realm by facilitating pedestrian movement and lowering vehicle traffic volumes and speeds. Previous research looked at how the behaviour and perceptions of pedestrians, vehicle drivers and pedal cyclists, vary with the introduction of elements of shared space. The aim of this study is to extend this analysis to Powered Two-Wheeler (PTW) riders, who are a road user group that is often overlooked. The study consists of two parts. The first one conducts a video observation analysis of the behaviour of PTW riders before and after the redevelopment of the Exhibition Road site in London’s South Kensington area to a layout with shared space elements, and looks at changes in key variables, such as flow and speed. The second part, then, provides an insight into the perceptions of PTW riders through a generic stated-preference survey investigating their “willingness to share space” with vehicles and pedestrians. The results show that PTW riders appear to treat shared space features more like motorised users rather than non-motorised ones. Indeed, lower PTW flows and speeds and fewer overtaking manoeuvres are recorded on Exhibition Road post-redevelopment, while lower willingness to share is expressed when large numbers of pedestrians and static obstacles (such as trees, seating and fountains) are present. On the other hand, PTW riders are more positive towards shared space elements if the design provides ample space and a smooth pavement surface.     

Exploring the space between words and meaning: Understanding the relational sensibility of surf spaces

This paper explores the potential of the written word to evoke emotional engagement with place. Through focussing on the relational sensibilities created through the act of surfing, the paper seeks to explore how these emotions are articulated by surfers in order to share their feelings with others. In doing so it draws attention to the ‘intersubjective space’ (after Thrift, 1996) between writer and reader and its potential to overcome the paradox of representation. In this space the written word has the potential to combine with readers' own experiences, however indirect or tangential, to create a currency of communicated lived experience. In this space, knowledge of surfing is co-created by writer and reader (or by surfer and non-surfer) and becomes freighted with empathic resonance. In order to explore whether the potential of this space can be realised, the paper presents examples of surf writing which seek to communicate the relational sensibility of surfing and asks the reader: can ‘only a surfer know the feeling’?     

Shared leadership and team effectiveness: The examination of LMX differentiation and servant leadership on the emergence and consequences of shared leadership

This study examined the effects of leader–member exchange (LMX) differentiation on team-shared leadership and team effectiveness. Drawing on the group engagement model, we suggested that LMX differentiation negatively affects team-shared leadership and team effectiveness (i.e., team performance and team organizational citizenship behavior [OCB]). Servant leadership weakens the negative effects of LMX differentiation on shared leadership. We tested our predictions using data from a sample of 336 salespersons nested in 110 sales teams in China. We found that shared leadership mediated the relationships between LMX differentiation with both team performance and team OCB. In addition, servant leadership moderated the relationship between LMX differentiation and shared leadership and the indirect relationship between LMX differentiation with both team performance and team OCB.     

Behavioural analysis of interactions between pedestrians and vehicles in street designs with elements of shared space

This paper describes the development and implementation of qualitative behavioural criteria in order to analyse the conduct of pedestrians and vehicles when they are required to interact with each other, with particular interest to street designs with elements of shared space. The new behavioural analysis technique is developed by identifying the fundamental principles that underpin existing traffic analyses, such as traffic conflicts techniques, and adapting those to a qualitative framework that describes the mindset and rationale of road users. The technique is then applied to a case study in London, using video data from periods before and after the redevelopment of the Exhibition Road site from a conventional dual carriageway to a modern design with some elements of shared space. With the main goals being to assess the pedestrians’ confidence and the vehicles’ tolerance/patience when forced to interact with each other, behavioural trends are related to instantaneous characteristics of the vehicle flow (vehicle approach speed and traffic density). The data produced are used to develop and validate qualitative behavioural relationships for pedestrian–vehicle interactions, as well as location-specific conclusions for the Exhibition Road site.     

Close interpersonal proximity modulates visuomotor processing of object affordances in shared,social space

Research suggests that the human brain codes manipulable objects as possibilities for action, or affordances, particularly objects close to the body. Near-body space is not only a zone for body-environment interaction but also is socially relevant, as we are driven to preserve our near-body, personal space from others. The current, novel study investigated how close proximity of a stranger modulates visuomotor processing of object affordances in shared, social space. Participants performed a behavioural object recognition task both alone and with a human confederate. All object images were in participants’ reachable space but appeared relatively closer to the participant or the confederate. Results revealed when participants were alone, objects in both locations produced an affordance congruency effect but when the confederate was present, only objects nearer the participant elicited the effect. Findings suggest space is divided between strangers to preserve independent near-body space boundaries, and in turn this process influences motor coding for stimuli within that social space. To demonstrate that this visuomotor modulation represents a social phenomenon, rather than a general, attentional effect, two subsequent experiments employed nonhuman joint conditions. Neither a small, Japanese, waving cat statue (Experiment 2) nor a metronome (Experiment 3) modulated the affordance effect as in Experiment 1. These findings suggest a truly social explanation of the key interaction from Experiment 1. This study represents an important step toward understanding object affordance processing in real-world, social contexts and has implications broadly across fields of social action and cognition, and body space representation.     

Shared spatial representations for numbers and space: the reversal of the SNARC and the Simon effects

In 4 experiments, the authors investigated the reversal of spatial congruency effects when participants concurrently practiced incompatible mapping rules (J. G. Marble & R. W. Proctor, 2000). The authors observed an effect of an explicit spatially incompatible mapping rule on the way numerical information was associated with spatial responses. The authors also observed an effect of an incompatible numerical mapping rule (if smaller than 5, press right; if larger than 5, press left) on the Simon effect. This effect was observed only when both tasks used the same effectors. The results point to a shared spatial representation for explicit spatial information (locations) and implicit spatial information (numbers).