I can't say I agree with this. Maybe you're thinking of UI, which I would agree can be very subjective.
Great UX, on the other hand, in the most simple possible terms, is the application of the golden rule to any interactive system: software, gadget, subway system, what have you. "If I had to use this thing, how would I want it to work?"
As a result, it's a pretty simple thing to test: how does this implementation enhance or detract from the user's ability to do what they're trying to do?
The degree of impact may be subjective, but I think it's pretty easy to tell when something is user hostile or user friendly.
The only way that UX can be globally optimal is if all users share the same goals, the same skills and understanding, the same capabilities (browser caps, etc.).
In the real world, where people have at least slightly different goals, are more or less sophisticated, and sometimes use IE6, compromises -- sometimes deep ones -- must be made.
For example, on our ecommerce site, we've got at least two very different user personas. One is what you might think is typical -- an end-user who browses, trying to figure out what to buy. The other is a purchasing manager, simply working his way down a purchase order. In many parts of the process these two people have very different needs. Obviously we want to try to cater to both of them, but multiplying the options in itself has effect on the UX.
>how does this implementation enhance or detract from the user's ability to do what they're trying to do?
If you're capitalistic about things though sometimes you want to do what will hinder your user's ability to fulfill their goal.
For example at the supermarket - I want to get milk and get away quick but the supermarket wants me to go through the whole store and be confronted with offers and the smell of the instore bakery, etc.. My experience is frustrated on purpose to benefit the business financially.
Similarly with "checkout" offers on a sales website. One particular printer makes you manually leaf through about 12 pages of offers after you've confirmed your purchase - it's a poorer UX (IMO) but will benefit the business.
Others will argue, this last case say, is an improved UX as I get the chance to bag offers I perhaps hadn't noticed. Thus it's subjective.
I can't say I agree with this. Maybe you're thinking of UI, which I would agree can be very subjective.
Great UX, on the other hand, in the most simple possible terms, is the application of the golden rule to any interactive system: software, gadget, subway system, what have you. "If I had to use this thing, how would I want it to work?"
As a result, it's a pretty simple thing to test: how does this implementation enhance or detract from the user's ability to do what they're trying to do?
The degree of impact may be subjective, but I think it's pretty easy to tell when something is user hostile or user friendly.