Glossary of Data Variables for Fatal and accident causation ... - ERSO

7.13 Safetynet accident causation system (SNACS)
Database operation manual
The classification scheme of SNACS contains two different sections. These
sections are labelled “critical events” and “causes”. The “critical events” are
used to classify the empirical material, i.e. the observable consequences of a
dysfunctional behaviour: this is what is visible when an observer arrives at the
scene of an accident. The “causes” are used to classify all the factors which can
be used to describe what has brought about, or can bring about, these effects.
The “causes” are what the investigator brings with him/her to the scene, the preunderstanding
of possible causes/reasons.
There are both general and specific “critical events”. There are eight different
general “critical events”, and then each general “critical event” has a subset of
specific “critical events” which belong to the general “critical event”. The
difference between general and specific “critical event” is a degree of
information. The specific “critical event” describes more delimited states than
the general ones. If the investigator has sufficient information about the accident
to choose a specific “critical event” then that is what s/he should do. If there is
not enough information, the investigator has to stick with a general “critical
event”.
The construction of a linking chain is driven by software. By selecting one of the
eight general “critical events” it generates another form with the possibility to
choose in a range of specific “critical events” (radio buttons) or in a range of
possible general “causes” (buttons). If the user chooses a specific “critical
event”, the linking chain is terminated and saved in the database. If the user
chooses a generic “cause”, a new form is opened with its own specific “causes”
associated (radio buttons) and other relative general “causes” that can be
raised from the one actually selected. The linking chain grows in this way until
the user chooses a specific “cause”. Each choice that adds an element in the
linking chain needs a comment to be inserted.
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