A context for error: using conversation analysis to represent and analyse recorded voice data

Recorded voice data, such as from cockpit voice recorders (CVRs) or air traffic control tapes, can be an important source of evidence for accident investigation, as well as for human factors research. During accident investigations, the extent of analysis of these recordings depends on the nature and severity of the accident. However, most of the analysis has been based on subjective interpretation rather than the use of systematic methods, particularly when dealing with the analysis of crew interactions. This paper presents a methodology, called conversation analysis, which involves the detailed examination of interaction as it develops moment-to-moment between the participants, in context. Conversation analysis uses highly detailed and revealing transcriptions of recorded voice (or video) data that can allow deeper analyses of how people interact. The paper uses conversation analysis as a technique to examine CVR data from an accident flight. The focus accident was a controlled flight into terrain event involving an Israel Aircraft Industries Westwind 1124 jet aircraft, which impacted terrain near Alice Springs on 27 April 1995. The conversation analysis methodology provided a structured means for analysing the crew’s interaction. The error that contributed directly to the accident, an incorrectly set minimum descent altitude, can be seen as not the responsibility of one pilot, but at least in part as the outcome of the way the two pilots communicated with one another. The analysis considered the following aspects in particular: the significance of overlapping talk (when both pilots spoke at the same time); the copilot’s silence after talk from the pilot in command; instances when the pilot in command corrected (repaired) the copilot’s talk or conduct; and lastly, a range of aspects for how the two pilots communicated to perform routine tasks. In summary, the conversation analysis methodology showed how specific processes of interaction between crew members helped to create a working environment conducive to making, and not detecting, an error. By not interacting to work together as a team, pilots can create a context for error. When analysing recorded voice data, and especially for understanding instances of human error, often a great deal rests on investigators’ or analysts’ interpretations of what a pilot said, or what was meant by what was said, or how talk was understood, or how the mood in the cockpit or the pilots’ working relationship could best be described. Conversation analysis can be a tool for making such interpretations.This report was commisioned by Australian Transport Safety Burea

The possibility of a British earned income tax credit

The possibility of an earned income tax credit, based on the US model, is currently high up the British political agenda. This paper examines the strengths and weaknesses of the current British system of in-work benefits, before reviewing the effectiveness of the US Earned Income Tax Credit (EITC) scheme. The British and US systems are then directly compared in terms of the net income delivered and the effective tax rate (net benefit deduction rate). Although the evidence in favour of a US-style EITC is weak, two possible variants are considered. The paper concludes that the only future for an EITC is probably as a partial scheme, linked to the amalgamation of in-work and out-of-work benefits, which removes wage subsidisation from the sphere of social security by means of a semi-individualised tax credit. Even so, the same goals could be achieved through the benefit system.

Recovery, Renewal, and Resiliency: Gulf Coast Small Businesses Two Years Later

Presents findings from a survey of small business owners about the state of the local economy immediately following and in the two years since Katrina made landfall

Tilted Interferometry Realizes Universal Quantum Computation in the Ising TQFT without Overpasses

We show how a universal gate set for topological quantum computation in the Ising TQFT, the non-Abelian sector of the putative effective field theory of the $\nu=5/2$ fractional quantum Hall state, can be implemented. This implementation does not require overpasses or surgery, unlike the construction of Bravyi and Kitaev, which we take as a starting point. However, it requires measurements of the topological charge around time-like loops encircling moving quasiaparticles, which require the ability to perform `tilted' interferometry measurements.Comment: This manuscript has substantial overlap with cond-mat/0512066 which contains more physics and less emphasis on the topology. The present manuscript is posted as a possibly useful companion to the forme

On the simulation of space based manipulators with contact

An efficient method of simulating the motion of space based manipulators is presented. Since the manipulators will come into contact with different objects in their environment while carrying out different tasks, an important part of the simulation is the modeling of those contacts. An inverse dynamics controller is used to control a two armed manipulator whose task is to grasp an object floating in space. Simulation results are presented and an evaluation is made of the performance of the controller