Compositionality Meets Belief Revision: a Bayesian Model of Modification

The principle of compositionality claims that the content of a complex concept is determined by its constituent concepts and the way in which they are composed. However, for prototype concepts this principle is often too rigid. Blurring the division between conceptual composition and belief update has therefore been suggested (Hampton and Jönsson 2012). Inspired by this idea, we develop a normative account of how belief revision and meaning composition should interact in modifications such as “red apple” or “pet hamster”. We do this by combining the well-known selective modification model (Smith et al. Cognitive science 12(4):485–527 1988) with the rules of Bayesian belief update. Moreover, we relate this model to systems of defeasible reasoning as discussed in the field of artificial intelligence.

“An Imagined Border of Safety, Humanitarian Relief, and Creativity”: J.M. Design Studio’s Other Border Wall Project

In April 2017, J.M. Design Studio—three Pittsburgh-based artists and designers—responded to the Customs and Border Protection's public request for proposals for a wall along the US-Mexico border. J.M. Design Studio then announced their own call for more border "wall" proposals from other artists. The following commentary details these prototype concepts and tracks the executive policies and rhetoric that established a foundation for the border wall. This commentary also shows how J.M. Design Studio’s prototype submission and the subsequent artistic platform they initiated both model how creative connection and the co-option of established public channels are themselves acts of political resistance in an era of disrupted democratic participation and ossified partisanship.

Promoting Situation Awareness

Crisis communicators and journalists need stable structures to handle social media content in emergencies, but struggle with information overload. The usability of a tool intended to support information gathering was investigated by conducting two usability tests (low- and high-fidelity prototypes) with journalists. The aims were to investigate how well the design reflected users' general mental models of emergency work, and how it responded to the specific requirements set by work in high-stress surroundings. Tests were conducted in a laboratory. Participants understood the main prototype concepts, but struggled with time-consuming tasks, for instance, those related to saving content or evaluating information quality. To provide good situation awareness - and to fit in with user expectations - a system should gather information from several social media outlets and allow for varying possible user modes. However, system designers need to carefully balance between including necessary features and avoiding tasks that require complex manual actions.

Teaching Entrepreneurial Action Through Prototyping: The Prototype-It Challenge

This article outlines a novel approach to engaging entrepreneurship students in a hands-on, action-oriented prototyping exercise. The pedagogical focus of the Prototype-It Challenge is on the relationship between prototyping and entrepreneurial action, and specifically the value of basic prototypes in opportunity identification and opportunity evaluation. Working in teams, students prototype concepts to address a pressing public health challenge (vitamin D deficiency in youth leading to increased risk of heart and bone disease) and then get immediate feedback from a video of outspoken 10- to 12-year-old children on the desirability of their concepts. The session, which takes only 75 to 90 minutes in its entirety, emphasizes prototyping as a vital process to explore, develop, and evaluate entrepreneurial opportunities. Because of its generalizability, the Prototype-It Challenge has been successfully leveraged to meet learning objectives across diverse teaching environments, including undergraduate, MBA, and executive-level entrepreneurship programs.

Generator Collector Brush Holder Testing and Design Improvements

Electric generators and synchronous motors with static excitation use rotating slip rings (also known as collector rings) and stationary carbon brushes to transfer the field current from the stationary exciter to the rotating generator field. The carbon brushes experience wear from both mechanical friction and electrical contact with the rings. Therefore, the brushes need to be periodically inspected and replaced. This is often the most frequent maintenance activity for an electric generator. It is generally recognized that if brushes are not changed when worn down, this can result in a damaging condition called a flashover that will usually force the generator offline. Several collector flashovers were investigated to look for other common characteristics with the aim of reducing the risk of flashover occurrence and improving generator reliability. Some features of the generator collector brush holders were identified as significant contributors to collector flashovers and also to other, more common maintenance problems. Several brush holder designs were evaluated with regard to these features and also with regard to feedback received from operators. In addition, an in-house test rig was developed and used to compare multiple, existing brush holder designs and new prototype concepts for brush wear rate and current selectivity. This work led to a new brush holder design that addresses these concerns and has subsequently been successfully tested in a laboratory and at a customer site. That new brush holder design is being applied to both new units and as a retrofit to in-service aftermarket generators.

Rule and similarity as prototype concepts

There is a continuum between prototypical cases of rule use and prototypical cases of similarity use. A prototypical rule: (1) is explicitly represented, (2) can be verbalized, and (3) requires that the user selectively attend to a few features of the object, while ignoring the others. Prototypical similarity-use requires that: (1) the user should match the object to a mental representation holistically, and (2) there should be no selective attention or inhibition. Neural evidence supports prototypical rule-use. Most models of categorization fall between the two prototypes.