If I may interject a few additional comments:
 
>Touchscreens are a bit more intimate and allows the visitor to connect with
>what is on the screen.
 
Touchscreens are more common in commercial applications (e.g. ATMs at banks)
and so more visitors may be familiar with the interface.
 
>Replacing a touchscreen can range from the cost of the screen ($500-$1000),
but
>this may only have to be done once during the life of a monitor (say 5
years).
 
We have been using touchscreens on some 19" monitors. These cost us $1100
each and we have had failures more frequently than indicated above. When a
touchscreen fails, the entire monitor must come out, and may or may not be
serviceable on site. Back-up equipment is necessary. You cannot use a
protective glass cover over your monitors if your interface is a
touch-screen, so vandalism is always possible (and we've experienced that
too.) We do not intend to use touch-screens in any of our next-generation
exhibits.
 
>Trackballs, joysticks, mice wear out under constant use in a high traffic
institution.
 
Quite true. Trackballs require more frequent maintenance, but there is at
least one very heavy duty type that we have started using and that seems to
stand up to younger visitors. These cost us about $110 each.
 
The popular and less expensive ($95 each) retail variety (the size of a
billiard ball) suffers from a design that places a pc board just beneath the
ball. Repeated pounding cracks the board. On the plus side, the manufacturer
of this device replaces broken devices under the terms of their 5-year
warranty. We have many back-ups and cycle these to the mfgr. So far, they
have been very cooperative.
 
The real trick is in the programming and in the front-end. If your interface
is successful, the unitiated will find navigation intuitive (which means less
banging in attempts to get the thing to do something...)
 
BTW: Younger visitors (according to our studies) are more likely to use any
device than older vistors, so there is the added challenge to engage those
unfamiliar with or intimidated by computers, period.
 
Bottom line: visitor evaluation of all aspects is required.
 
best regards,
 
Kevin Coffee
American Museum of Natural History
[log in to unmask]