On Oct 7, 12:41 am, Phil wrote:

As I understand it, the whole right-brain left-brain thing has pretty
much been discredited. The more recent research shows that any
complex task engages both sides of the brain. I don't think there
were too many neuroscientists who ever embraced the idea that one side
does "art" and the other side does "math" anyway.

I think the biggest difference between steam gauges and digital
displays is that steam gauges give you a value in context of a
spectrum of values. When you look at a analog tachometer, you can see
the where the needle is compared to the minimum and maximum values.
If you are trying to set 75% power, it might be useful to have the
information presented that way, because you can see where 3/4 of the
range is. Same with airspeed. You can see how close you are to the
red arc, where you are in the green arc, etc.

On the other hand, why would you want to see altitude displayed with
needles? If I want to fly at a specific altitude, I am looking for a
number, not a position in a range. I think the traditional altimeter
was made the way it was because it was the easiest way to get a
mechanical instrument to display the information that way, not because
it was the easiest way to digest the information.

Ideally, every instrument should be designed to convey the appropriate
information in a way that is conducive to how that information is
going to be used. If you just need a value, then a digital display of
a number make sense. If you need to have a sense of where you are
relative to minimum and maximum, then a display showing relative
position in a range should be used. The nice thing about a
computerized display is it can be set up to display the information
either way.

Phil- Hide quoted text -



I agree with this statement. A needle is a graphical display of a
numerical value. A picture is worth a lot more than just the number.
By presenting just the numeric value you are taking away a lot of
useful information about neighboring values. Its like a GPS that shows
the lat-lon values instead of a moving map. The only exception I can
think of is the altimeter and VSI reading, where a numeric display may
be best.

I once saw a car that had a numeric RPM display. During accelerations
all digits were moving so fast you could not make anything from it.