Tom Anderson wrote:
On Tue, 10 Jul 2007, Paul Corfield wrote:

I think people are forgetting that the security situation and
assessment of risk to the tube network means that certain things
*have* to be said. You only need to look at the impact of security
alerts on the service just because people have left bags, boxes and
other items lying around. The fact people leave them behind warrants a
reminder!

If *and only if* those announcements are actually effective. The whole
point of the whinge is that because people hear them every five minutes
every day, they tune them out, and they have no effect. If this is true,
the announcements are a Bad Thing; if not, they're a Good Thing. Until
someone points us to a study which actually determines this, we're all
****ing in the wind.

Don't know if there have been any specific studies about those
announcements. But it has long been axiomatic in human factor research
that too many warnings causes people to start ignoring the warnings.

You could repeat the notice "This is a security announcement: Please do
not leave personal belongings unattended" every few minutes. If it is
ignored you are no worse off than not making the announcement from the
point of view of leaving bags unattended. But when you have a really
important security announcement, lots of people will ignore it.

I know that at my local station when I hear "this is a special
announcement" it means just the opposite and I can safely tune out.
--
Michael Hoffman