In the states, there is an ongoing debate on that...additionally, there is a debate on what separates segmentation from Intarsia...
At the magazine, we define segmentation as cutting all the pieces out of the same piece of wood without regard for color or grain changes.
Intarsia is cut from several pieces of wood, and assembled to make best use (visually) of the grain direction. Judy Gale Roberts, a popular Intarsia artist in the states, uses predominately Western Red Cedar for all of her projects. It offers enough natural colors that she can do what she needs to. Neal Moore's latest attempts at intarsia are done using poplar and stains. But since the pieces are cut individually, he has the opportunity to use the grain to accent the piece.
Neal actually wrote a book on segmentation, and since I'm staring at one of the pieces he did that I appropriated for my office, I would rank it up with all of the Intarsia art I've seen. He has mastered the use of color, texture, and depth. I firmly believe that you can't compare the two arts; they are too different. Segmentation, while it doesn't require as much cutting skill (It will ALWAYS fit together properly), does require a much greater understanding of color and texture.
Sorry it's long winded...but like I said, there are strong feelings about that over here. Many people consider segmentation "beginner intarsia" but that couldn't be further from the truth in my humble opinion.
Bob