Police forces in late medieval Italy: Bologna, 1340–1480

Police forces (birri) in Italian cities in the fourteenth and fifteenth centuries were composed of outsiders, non-natives, employed on short-term contracts, usually of six months’ duration. There was therefore a huge circulating pool of these patrolmen, sergeants and constables, moving from city to city. These groups have been little studied, and are often assumed to be vile, odious and little better than criminals. This article draws on surviving records in one city of northern Italy (Bologna), to analyse the composition of these groups and especially their cosmopolitan, international memberships, which grew consistently across the period before tailing off towards the end of the fifteenth century. The article uses frames of reference from migration studies, particularly the large Balkan migrations of the fifteenth century, and from identity studies, to chart and assess the trajectory and reception of non-Italians among these groups. The article thus extends what is known about the integration of migrants in late medieval Italy, goes beyond what is known about the documentation of identity in the Middle Ages and raises questions about the quality of policing provided by multinational groups.     

Efficient crossover designs in the presence of interactions between direct and carry-over treatment effects

Crossover designs, or repeated measurements designs, are used for experiments in which t treatments are applied to each of n experimental units successively over p time periods. Such experiments are widely used in areas such as clinical trials, experimental psychology and agricultural field trials. In addition to the direct effect on the response of the treatment in the period of application, there is also the possible presence of a residual, or carry-over, effect of a treatment from one or more previous periods. We use a model in which the residual effect from a treatment depends upon the treatment applied in the succeeding period; that is, a model which includes interactions between the treatment direct and residual effects. We assume that residual effects do not persist further than one succeeding period.A particular class of strongly balanced repeated measurements designs with n=t² units and which are uniform on the periods is examined. A lower bound for the A-efficiency of the designs for estimating the direct effects is derived and it is shown that such designs are highly efficient for any number of periods p=2,…,2t.     

Peak performing organisations

The literature on organisational performance is riddled with measurement problems that cannot easily be solved. In contrast we argue that elite theory in terms of performance can be more easily measured by the win record of sports organisations. Accordingly, this article argues that certain organisational peak practices are key to understanding how peak performance is sustained. Through data collected from the top ten sports organisations in the world we introduce the embryonic theory of Peak Performing Organisations (PPO). Sustained PPO practices offer more robust outcomes than the genre of High Performing Organisations.     

Modeling of rates over a hierarchical health administrative structure

Identifying the distribution of the incidence rate of a disease over a region is a prediction problem where area‐specific random effects are to be estimated. The authors consider the inclusion of such effects at different levels of a hierarchical health administrative structure. They develop inference procedures for this type of multi‐level model and show that the predicted rates are approximately weighted sums of the crude rates obtained by pooling data on each level of the hierarchy. Their techniques are illustrated using infant mortality data from British Columbia.     

The SAM Framework: Modeling the Effects of Management Factors on Human Behavior in Risk Analysis

Complex engineered systems, such as nuclear reactors and chemical plants, have the potential for catastrophic failure with disastrous consequences. In recent years, human and management factors have been recognized as frequent root causes of major failures in such systems. However, classical probabilistic risk analysis (PRA) techniques do not account for the underlying causes of these errors because they focus on the physical system and do not explicitly address the link between components' performance and organizational factors. This paper describes a general approach for addressing the human and management causes of system failure, called the SAM (System-Action-Management) framework. Beginning with a quantitative risk model of the physical system, SAM expands the scope of analysis to incorporate first the decisions and actions of individuals that affect the physical system. SAM then links management factors (incentives, training, policies and procedures, selection criteria, etc.) to those decisions and actions. The focus of this paper is on four quantitative models of action that describe this last relationship. These models address the formation of intentions for action and their execution as a function of the organizational environment. Intention formation is described by three alternative models: a rational model, a bounded rationality model, and a rule-based model. The execution of intentions is then modeled separately. These four models are designed to assess the probabilities of individual actions from the perspective of management, thus reflecting the uncertainties inherent to human behavior. The SAM framework is illustrated for a hypothetical case of hazardous materials transportation. This framework can be used as a tool to increase the safety and reliability of complex technical systems by modifying the organization, rather than, or in addition to, re-designing the physical system.     

Evaluation of treatment programs for persons with severe mental illness: moderator and mediator effects

This study evaluated several statistical models for estimating treatment effects in a randomized, longitudinal experiment comparing assertive community treatment (ACT) versus brokered case management (BCM). In addition, mediator and moderator analyses were conducted. The ACT clients had improved outcomes in terms of housing and psychiatric symptoms than BCM clients. Case management housing assistance and financial assistance partially mediated housing outcomes. No reliable mediators were found for psychiatric symptoms, and no reliable moderators were found for either housing or psychiatric symptoms. The study also made several important methodological advances in the analysis of longitudinal data in randomized experiments.