Easy to tell odd man out among Turner quartet

The job of the Turner Prize jury in Britain isn't just to come up with four lively and upcoming artists. They've also got to come up with four reasonably distinct ones. These artists will appear in a show together at Tate Britain for three months, and a stream of visitors will be invited to compare them. It's important they are able to tell the difference between the entries.

This year's foursome is Roger Hiorns, Enrico David, Lucy Skaer and Richard Wright. There's plenty of common ground. There are wall markings (Skaer, Wright); there are liquid shapes (Wright, Hiorns); there are powdered materials (Hiorns, Skaer). There are points at which three of the four could be the same artist. Still, it doesn't mean the odd man out is the best.

The odd man out is David, and his work is a bit silly. It's a sort of Punch-and-Judy psychodrama. You have a tableau made of miscellaneous effigies. There are propped-up canvases with cartoony characters. There's a stuffed black-cloth figure. There are papier mache puppets. It's rude. It's crazy. It's quite inventive. But there could be more of this stuff, or less of it, and it wouldn't make any difference.

Skaer's work: what's it about? Do I care enough to do the homework? There's always some background thinking, tenuously connected to a curious exhibit. There's a group of 26 replicas of that modernist classic, Brancusi's Bird in Flight, but made from coal dust and resin. Pretty ... but why? There's the huge real skull of a sperm whale hidden inside a chamber, and glimpsed only through vertical slits. Startling ... but why? I feel sure she's got an interesting mind. I'm not sure it's the mind of an artist.

Hiorns' main piece almost fills his allotted space: it's a swirling sea or landscape, made of finely powdered stuff, poured on to the floor. It lies there messy and fragile at your feet.

Hiorns' art also puts its faith in what you might call the hidden ingredient. What is this grey powder? Check the label. "Atomised passenger aircraft engine." What? Was there a momentary flinch when you thought it was actually passenger that had been atomised? But no, this dust is only the engine of a passenger aircraft. So what, though? It could be any kind of metal, ground down. Some connotation of plane crash? Don't try to give us the willies.

Wright has the longest odds, and I fear he won't be much of a favourite with the public.

His art is precise and laconic. But stand still for a while. Wait for his room to empty (it probably will). Involve. Wright takes a bare room and animates its space with tactical wall markings.

He fills one wall here with a vast, centred, symmetrical design. It's painted in gold leaf. It's enormously elaborate and detailed. On the opposite wall, high up above the doorway, there is a pair of small red explosive insignia. And between them the empty space of the gallery is held and balanced. Beyond that, I don't have much to say about this work - except that it seems to be in perfect focus, and I kept going back.

The Turner Prize will be announced on December 7; the exhibition runs until January 3.

- INDEPENDENT