terminological obscurity

["Martin v. Löwis"]

Arthur wrote:
> Given a tuple (1,1,1) representing  X,Y,Z corrdinates, I - for one -
> have trouble explaining the heterogenous nature of the data, outside
> of the "tuple" sense of the word. 

Most people tend to think that "height" and "width" are different
concepts. I am 199cm high, not 199cm wide. So my extension, in Y
direction, is 199cm - not my X extension, nor my Z extension.

The fact that I use cm to measure X, Y, and Z still doesn't make
them homogenous. If they were homogenous, I could add many more
of these in a meaningful way (yes, I know that some people have
applications where you process arbitrary numbers of coordinates.
typically, 2D, 3D, and 4D are entirely different things).

> Similarly, "conceptual homogeniety" in this context can mean anything
> - to me, pretty much  -, within the limit of describing data elements
> that it might be  sensible to handle together in a list.   

A collection of data is homogenous if their relative position in
the sequence does not matter much. They are heterogenous if different
elements have entirely different meanings.

Regards,
Martin