...Oh no, not this discussion again, the last time we had this it ended in flaming and yelling and other nasty things.

@drGeep, you say that 1 poserunit is 100 inch, but in the Poser(5,6,7) manual it says it's 8.6 feet or 262,128 centimeters. Who is right? I agree that 100 inch is much more elegant, but I'm tended to follow the manual (They don't say RTFM for nothing, don't they?)

As a furniture designer I've always checked ergonomicsdata to make a good design. This data are based on statistic wealth surveys as well as army recruit data. These data are not fixed or static, they differ from country to country, and in time. In times of economic wealth people are taller and in times of depressions people are smaller. So people in the middle-ages were actually a lot smaller than people are today.
These data are also separated  in female and male proportions and are based on a Gause-scale: there is a minimum, an average and maximum dimension: Someone who is smaller than the minimum or taller than the maximum, can(!)  have a growth disfunction. But as I said this differs from country to country: In China I'm a giant, in my own country (Holland) I'm just above average. (As an anomalie: the tallest man on earth lives in China: 2.4m, or about 8 feet!)
But back to the design topic: I've used the Posermanual PNU-explanation as starting point for my chairs, but when I imported an used them in Poser with Vicky3 or Michael3 they were always too small, so I had to scale them up a little. So the conclusion was that Daz made them too big considering the official Poser scale. (Which was also Stahlratte's conclusion, but that was a discussion about proportion, on which I won't burn my fingers on!, this is about scale)
What is my advice on scale: Well, don't use any! When you import a Poser-model in a 3D-modeller, it's always very small, scale it up to a workable size and model the clothes and props and furniture around just the way you like it, don't think that something has to be exactly four inch or 32cm. just model something that "looks" good. In this way, your design will look far more natural than when you try to achieve some standard proportions. When you want make a chair: pose your figure in a sitting position export it, and model the chair under her or his buttocks, it will always fit!
And if you really want to use exact dimensions: Decide yourself how long you want your figure to be: Draw a line of that height and scale your posermodel until it has the same height(note the amount you have to scale up) , model your props or clothes on the acquired dimensions and when you're finished  scale it down to the original size and export it. Once imported in Poser it has the right dimensions compaired to your model.

Best regards,

Bopperthijs.

-How can you improve things when you don't make mistakes?