Am 12.01.2015 um 02:03 schrieb Dale:

does CIE measure the rods/cones/LMS spectral sensitivity
chemically or by observer experiments?

CIE defines three curves, and these curves are standardized, not a
measurement procedure. They have only limited correlation to the cone
response curves or the absorption curves of the receptors in the eye.
Let it be as it is, these curves are official, and they are the base of
the XYZ colorspace.

Historically, they have been obtained from color-matching experiments
(with the limited technology available back then), where Y is
(proportional to) the luminance, and then normalizing the curves such
that the area under each curve is one.

I think rbar,gbar,bbar were designed to produce CIERGB
tristimulus values with the spectral power distributions of colors
perceived.

No. Besides, there is no single RGB space. RGB is a derived colorspace,
based on XYZ given three primaries.

I think, xbar,ybar,zbar were designed for XYZ tristimulus values,
particularly for the point of tristimulus vales with a luminous
function, Y.

No. X,Y,Z are *defined* by these curves.

Greetings,
Thomas