Equitability revisited: why the “equitable threat score” is not equitable

In the forecasting of binary events, verification measures that are “equitable” were defined by Gandin and Murphy to satisfy two requirements: 1) they award all random forecasting systems, including those that always issue the same forecast, the same expected score (typically zero), and 2) they are expressible as the linear weighted sum of the elements of the contingency table, where the weights are independent of the entries in the table, apart from the base rate. The authors demonstrate that the widely used “equitable threat score” (ETS), as well as numerous others, satisfies neither of these requirements and only satisfies the first requirement in the limit of an infinite sample size. Such measures are referred to as “asymptotically equitable.” In the case of ETS, the expected score of a random forecasting system is always positive and only falls below 0.01 when the number of samples is greater than around 30. Two other asymptotically equitable measures are the odds ratio skill score and the symmetric extreme dependency score, which are more strongly inequitable than ETS, particularly for rare events; for example, when the base rate is 2% and the sample size is 1000, random but unbiased forecasting systems yield an expected score of around −0.5, reducing in magnitude to −0.01 or smaller only for sample sizes exceeding 25 000. This presents a problem since these nonlinear measures have other desirable properties, in particular being reliable indicators of skill for rare events (provided that the sample size is large enough). A potential way to reconcile these properties with equitability is to recognize that Gandin and Murphy’s two requirements are independent, and the second can be safely discarded without losing the key advantages of equitability that are embodied in the first. This enables inequitable and asymptotically equitable measures to be scaled to make them equitable, while retaining their nonlinearity and other properties such as being reliable indicators of skill for rare events. It also opens up the possibility of designing new equitable verification measures.

An examination of actors that impact technology introduction to FM

Developing and implementing a technology for Facilities Management (FM) can be a complex process. This is particularly the case when a technology impacts on an organisation as a whole. There are often a number of relevant actors, internal and external to FM, who should be engaged. This engagement is guided by the strategy of the organisation which is led by top management decisions. Indeed, it is top management who have the final decision to implement a technology. Actors of top management and other relevant actors will have their own discourses toward the implementation of the technology based on how they foresee the technology befittingly benefitting the organisation. This paper examines actors who play a relevant and necessary part in supporting and implementing a technology to FM. It examines how an actor’s discourse toward the project inhibits or speeds up the implementation of a technology. The methods used for this paper are based on a two year case study in a FM department where a technology development was observed and interviews with key participants were conducted. Critical discourse analysis is used to analyse the data. Prominent discourses that emerge from the data are emphasised during the process of introducing the technology. This research moves beyond focusing purely on project successes but examines the difficulties and the hurdles that must be overcome to reach a successful technology implementation.

Microprocessor systems: an introduction

The aim of this book is to provide and introduction to microprocessor systems, their operation and design. It covers those topics needed by engineers and computer scientists who are interested in applying microprocessors in practical situations, namely computer hardware including logic and interfacing, software, in particular high level and assembly language programming, and the design and testing of such systems. The fundamental principles of micrprocessor systems are described and these are illustrated with reference to two microprocessors, the 32-bit MC68020 from Motorola and a single chip microcomputer, the 8051 from Intel; and in addition, interfacing to the general purpose STE bus is described. The details of the processors and the bus are concentrated in three chapters, thus allowing the presentation of the material to be independent of the microprocessors if that is desired, and permitting the specific details to be found easily.