The Tate Gallery has given a fair amount of space to the four shortlisted contenders for the Turner Prize, who are Christine Borland, Angela Bulloch, Cornelia Parker and Gillian Wearing. Each of them has, in effect, a one-woman exhibition. The show looks more generous than in recent years, though on inspection it's somewhat thin. Each of the individual displays is of about the standard that one finds in commercial galleries in London throughout the year. None of the exhibitors appears to have made a special effort for her appearance at the Tate. They simply don't look like prize-winners, though one of them will become famous, and pounds 20,000 richer, when Chris Smith announces her the winner at the usual lavish dinner on 2 December.

That event will be televised, and all through November carefully managed ''discussions'' about the Prize will take place in Belfast, Glasgow, Manchester, Southampton, St Ives and Sunderland (details from C4's internet site, I think all this publicity is crazy and not of real service to the cause of art. This is also the view of every single artist I have talked to about the Turner Prize over the years. Large sections of the public seem to agree. Meanwhile, the Tate and its satellite nouveau-riche organisation, the Patrons of New Art, continue to revel in the media attention. Their latest venture is a book by Virginia Button (Tate Gallery Publishing Ltd, pounds 16.95), announced as ''the first major book on the award". Since Button has been the administrator of the Turner Prize for the last five years, she is not an impartial historian. Her book is a publicity puff. The Tate ought to be more modest, for the record of the Turner Prize is not one of achievement.

Underachievement characterises the work of all four artists in this year's exhibition. There's not much in it, but on balance, I would give the Prize to Cornelia Parker over Gillian Wearing. The Tate's citation says that Wearing has been chosen "for the sustained development of her work in this year". They mean that she's getting better, and I agree with this view. It's hard to compare her video pieces with Parker's drawings and installation, but the latter are preferable. Parker has more artistic instinct and could have a longer career. A person wedded to video alone - as Wearing seems to be - will always have to contend with the inflexibility of the medium. She should consider drama or film.

Parker became known in 1991, when she persuaded the British Army to blow up a garden shed on her behalf, then gathered the fragments together and exhibited them at the Chisenhale Gallery. But how to present these bits of a controlled disaster? She decided to suspend them from the ceiling. Perhaps there was no alternative apart from strewing them on the floor, but sculptures hung from ceilings are rarely successful in artistic terms. At the Tate, Parker's Mass (Colder Darker Matter) looks more effective because its individual parts are horrifically black and give the spectator the frisson that always comes when we look at the remnants of a house that's been destroyed by fire. Mass consists of pieces of wood reduced to charcoal. She found them in Texas. They come from a Baptist church that had been struck by lightning.

This work is not sufficiently constructed. As with the Chisenhale shed, the burnt wood is suspended from the ceiling. This method is both the principle of the piece and its weakness. We imagine what part of the church the pieces of charcoal might once have been. Yet, formally speaking, they might have been arranged in lots of different ways. A further problem is that the piece is only interesting if one knows about the lightning strike. Parker's catalogues dutifully explain the origins of her works: otherwise we would not take much notice of her floating debris.

Explanations are found in compressed form in Parker's titles, and in captions helpfully supplied by the Tate. Thus, Negatives of Sound is subtitled "Black lacquer residue from cutting the original grooves in records". Other drawings are made with hair, snake poison, cocaine, "sheets starched with chalk made from the white cliffs of Dover" and so on. They don't add up to much, but one detects a sensibility and a willingness to explore different materials. Parker should experiment with everything she can lay her hands on. I literally mean her hands. Her future lies in the explorations she has been making in these drawings. At the moment, though, they are "hands-off" works, as we used to say in art school - not manual enough, as though they had been made with tweezers.

Gillian Wearing's two videos are Sacha and Mum and 60 Minutes Silence. In the first are a mother and daughter, alternatively affectionate and violent, kissing but also struggling. Wearing has made the tape run backwards and there's a nagging, broken soundtrack of her subject's cries, and more intimate noises. I prefer the hour- long video of 26 policemen and women, in three rows as if posing for a photo. Wearing persuaded them to stand still for an hour, but naturally, they can't manage it. So every little twitch or cough is enormously magnified in meaning, though such little movements of the body one knows to be next to nothing in themselves.

60 Minutes Silence is by far the most engaging work in the exhibition. The trouble is that it's a video, inherently a boring medium, which often thrives on mockery of things in life which are themselves boring. Fast and intelligent young people ought to see what video can do, then jettison it. I wish Christine Borland and Angela Bulloch seemed brighter and speedier. Borland shows replicas of death masks from different ethnic groups, found in a German museum. Bulloch has a large mixed-media floppy sculpture. It makes noises. These sculptures are not satisfactory contributions to contemporary art. Neither is the Turner Prize itself.

Tate, SW1 (0171 887 8000), to 18 Jan 1998.