I'm
not a big fan of group interviews as they often turn into an inquisition
of the worker most closely involved with the incident. I think the
time for group interviews is when the investigation process is at
the problem solving stage and brainstorming is called for. - Jeff
Depending
on the specific circumstances and schedule of an accident investigation,
investigators may choose to hold either individual or group interviews.
Generally, principal witnesses and eyewitnesses are interviewed
individually to gain independent accounts of the event.
However,
a group, interview may be beneficial in situations where a work
crew was either involved in or witness to the accident. Moreover,
time may not permit interviewing every witness individually, and
the potential for gaining new information from every witness may
be small.
Advantages
and disadvantages of both techniques are listed below. These considerations
should be weighed against the circumstances of the accident when
determining which technique to use.
Individual
interviews afford you the opportunity to obtain independent stories
and perceptions and to establish a one to one contact. On the
flip side more time is required and scheduling of a large number
of witnesses may be difficult.
Sometimes,
group interviews can corroborate testimony given by an individual,
but not provide additional details. The team should use their
collective judgment to determine which technique is appropriate.
Group interviews are more time efficient, and as many people are
contributing to the process you may get a more compete story.
Often one person's input jogs another's memory. The downside being
that you do not get independent stories and the more vocal members
of the group may dominate the conversation and anyone with a contradictory
opinion or an account may not get heard. As well, there is always
the risk of "group think."
Summarized from maiif.net (Marine Accident Investigation)
