A diversity-based approach to requirements tracing in new product development.

Production models emerged in recent times have stressed the need to face complex production contexts, characterized in particular by the rise in internal and environmental variability. In this work, a stylization of some elements concerning analysis and design of new products is given, and in particular those that involve definition and transfer phases in the development of innovative goods, where change and variability in requirements along development process are often high. This analysis has a twofold goal: first, to supply a conceptual frame for the close examination of some dynamics of requirement's integration into an artifact's design, in order to give account of their variability along development cycle; on the other side, to propose an approach based on simple similarity metrics, to be applied to linguistic descriptions of artifacts in the early phases of development process, in order to identify components in an artifact that undergo larger variability and therefore are to be paid more attention in the subsequent phases of life cycle.

Stochastic learning in co-ordination games : a simulation approach

In the presence of externalities, consumption behaviour depends on the solution of a co-ordination problem. In our paper we suggest a learning approach to the study of co-ordination in consumption contexts where agents adjust their choices on the basis of the reinforcement (payoff) they receive during the game. The results of simulations allowed us to distinguish the roles of different aspects of learning in enabling co-ordination within a population of agents. Our main results highlight: 1. the role played by the speed of learning in determining failures of the co-ordination process; 2. the effect of forgetting past experiences on the speed of the co-ordination process; 3. the role of experimentation in bringing the process of co-ordination into an efficient equilibrium

Coordination, Division of Labor, and Open Content Communities: Template Messages in Wiki-Based Collections

In this paper we investigate how in commons based peer production a large community of contributors coordinates its efforts towards the production of high quality open content. We carry out our empirical analysis at the level of articles and focus on the dynamics surrounding their production. That is, we focus on the continuous process of revision and update due to the spontaneous and largely uncoordinated sequence of contributions by a multiplicity of individuals. We argue that this loosely regulated process, according to which any user can make changes to any entry, while allowing highly creative contributions, has to come into terms with potential issues with respect to the quality and consistency of the output. In this respect, we focus on emergent, bottom up organizational practice arising within the Wikipedia community, namely the use of template messages, which seems to act as an effective and parsimonious coordination device in emphasizing quality concerns (in terms of accuracy, consistency, completeness, fragmentation, and so on) or in highlighting the existence of other particular issues which are to be addressed. We focus on the template "NPOV" which signals breaches on the fundamental policy of neutrality of Wikipedia articles and we show how and to what extent imposing such template on a page affects the production process and changes the nature and division of labor among participants. We find that intensity of editing increases immediately after the "NPOV" template appears. Moreover, articles that are treated most successfully, in the sense that "NPOV" disappears again relatively soon, are those articles which receive the attention of a limited group of editors. In this dimension at least the distribution of tasks in Wikipedia looks quite similar to what is know about the distribution in the FLOSS development process

Coordination, Division of Labor, and Open Content Communities: Template Messages in Wiki-Based Collections.

In this paper we investigate how in commons based peer production a large community of contributors coordinates its efforts towards the production of high quality open content. We carry out our empirical analysis at the level of articles and focus on the dynamics surrounding their production. That is, we focus on the continuous process of revision and update due to the spontaneous and largely uncoordinated sequence of contributions by a multiplicity of individuals. We argue that this loosely regulated process, according to which any user can make changes to any entry, while allowing highly creative contributions, has to come into terms with potential issues with respect to the quality and consistency of the output. In this respect, we focus on emergent, bottom up organizational practice arising within the Wikipedia community, namely the use of template messages, which seems to act as an effective and parsimonious coordination device in emphasizing quality concerns (in terms of accuracy, consistency, completeness, fragmentation, and so on) or in highlighting the existence of other particular issues which are to be addressed. We focus on the template "NPOV" which signals breaches on the fundamental policy of neutrality of Wikipedia articles and we show how and to what extent imposing such template on a page affects the production process and changes the nature and division of labor among participants. We find that intensity of editing increases immediately after the "NPOV" template appears. Moreover, articles that are treated most successfully, in the sense that "NPOV" disappears again relatively soon, are those articles which receive the attention of a limited group of editors. In this dimension at least the distribution of tasks in Wikipedia looks quite similar to what is know about the distribution in the FLOSS development process.commons based peer production; wikipedia; wiki; survival analysis; quality; bug fixing; template messages; coordination

Wikibugs: the practice of template messages in open content collections.

In the paper we investigate an organizational practice meant to increase the quality of commons-based peer production: the use of template messages in wiki collections to highlight editorial bugs and call for intervention. In the context of SimpleWiki, an online encyclopedia of the Wikipedia family, we focus on {complex}, a template which is used to flag articles disregarding the overall goals of simplicity and readability. We characterize how this template is placed on and removed from articles and we use survival analysis to study the emergence and successful treatment of these bugs in the collection.commons based peer production; wikipedia; wiki; survival analysis; quality; bug fixing; template messages; coordination

On bubbling dynamics generated by a stochastic model of herd behavior

This paper suggests a class of stochastic collective learning processes exhibiting very irregular behavior. In particular, there are multimodal long run distributions. Some of these modes may vanish as the population size increases. This may be thought of as "bubbles" persistent for a finite range of population sizes but disappearing in the limit. The limit distribution proves to be a discontinuous function of parameters determining the learn- ing process. This gives rise to another type of "bubbles": limit outcomes corresponding to small perturbations of parameters are different. Since an agent's decision rule involves imitation of the majority choice in a random sample of other members of the population, the resulting collective dynamics exhibit "herding" or "epidemic" features

On Bubbling Dynamics Generated by a Stochastic Model of Herd Behavior.

This paper suggests a class of stochastic collective learning processes exhibiting very irregular behavior. In particular, there are multimodal long run distributions. Some of these modes may vanish as the population size increases. This may be thought of as "bubbles" persistent for a finite range of population sizes but disappearing in the limit. The limit distribution proves to be a discontinuous function of parameters determining the learning process. This gives rise to another type of "bubbles": limit outcomes corresponding to small perturbations of parameters are different. Since an agent's decision rule involves imitation of the majority choice in a random sample of other members of the population, the resulting collective dynamics exhibit "herding" or "epidemic" features.

Overview on electrical issues faced during the SPIDER experimental campaigns

SPIDER is the full-scale prototype of the ion source of the ITER Heating Neutral Beam Injector, where negative ions of Hydrogen or Deuterium are produced by a RF generated plasma and accelerated with a set of grids up to ~100 keV. The Power Supply System is composed of high voltage dc power supplies capable of handling frequent grid breakdowns, high current dc generators for the magnetic filter field and RF generators for the plasma generation. During the first 3 years of SPIDER operation different electrical issues were discovered, understood and addressed thanks to deep analyses of the experimental results supported by modelling activities. The paper gives an overview on the observed phenomena and relevant analyses to understand them, on the effectiveness of the short-term modifications provided to SPIDER to face the encountered issues and on the design principle of long-term solutions to be introduced during the currently ongoing long shutdown.Comment: 8 pages, 12 figures. Presented at SOFT 202

Wikibugs: the practice of template messages in open content collections

In the paper we investigate an organizational practice meant to increase the quality of commons-based peer production: the use of template messages in wiki collections to highlight editorial bugs and call for intervention. In the context of SimpleWiki, an online encyclopedia of the Wikipedia family, we focus on {complex}, a template which is used to flag articles disregarding the overall goals of simplicity and readability. We characterize how this template is placed on and removed from articles and we use survival analysis to study the emergence and successful treatment of these bugs in the collection