A context for error: using conversation analysis to represent and analyse recorded voice data
Date
Authors
Nevile, Maurice
Walker, Michael
Journal Title
Journal ISSN
Volume Title
Publisher
Australian Transport Safety Bureau (ATSB)
Abstract
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.
Description
Keywords
Citation
Collections
Source
Type
Report (Commissioned)
Book Title
Entity type
Access Statement
Open Access
License Rights
DOI
Restricted until
Downloads
File
Description