The shortlisted artists for Tuesday's Turner Prize are less interested in conventional considerations of colour and form than in the circumstances in which work is produced and received. John Slyce talks to all four about how the meaning of their work depends on who is looking at it

For Christine Borland (b.1965), Glasgow School of Art greatly influenced her work. "Studying in a department called 'environmental art' where the emphasis was on working in public spaces, led me to consider what the public who share that space might be used to seeing. The answer was to try to always throw people back to refer to their own life situation," she says.

A continuing theme is linked to her museum research - the exploration of human identity and its loss. For After A True Story - Giant and Fairy Tales (1997) (above right), Borland researched the lives of a dwarf, Caroline Crachami and a giant, Charles Byrne. Presented in the form of a Victorian fairytale book, Borland's text recounts their exploited lives within the context of an early 19th-century study of anatomy. In fact both skeletons are still on display at the Hunterian Museum within the Royal College of Surgeons, Glasgow.

Borland has tried to retain a sense of dignity which was lost in earlier treatments of the pair (and their remains). She modelled the individual bones in clay, placed them on glass shelves and covered them with dust. After removing the bones their negative image casts shadows on the walls. Caroline's dwarf image emanates from a shelf set at a height near her own while Charles towers eight feet high. Highlighting the distance between "copy" and "original", what we see is a shadow cast by the traces of dust left by a clay model.

ÖйúAƬ

In The Dead Teach the Living (above) Borland goes further. During a visit to the Anatomical Institute in Munster, Germany, she was fascinated by life-size busts representing various "ethnic types" taken from death masks earlier this century. As the institute's records were destroyed during the war, Borland was left to speculate as to their pedagogical use. Research showed that in the 1920s/30s the faculty was a centre for the study of "racial hygiene" and eugenics. Borland used a computer-assisted machine to replicate the busts in translucent plastic, removing the subjective hand of both artist and anatomist.

Angela Bulloch (b.1966) demonstrates not only how challenging contemporary art can be, but also how much fun. A graduate of Goldsmiths College, London University, Bulloch is interested in the operation and impact of systems - mechanical, linguistic, and social.

ÖйúAƬ

The question to ask is "How does it work?" not "What does it mean?" Superstructure with Satellites (see right) is a musical sculpture comprised of a daisy chain of bean bags joined by three large primary coloured doughnut shapes.

A series of switches, triggers and magic eyes serve as satellite links to be discovered. As you move through the room - becoming yourself a satellite of this sonic system - there is the opportunity to set off three soundtracks that Bulloch has composed taking samples from various musical sources. The coincidence of the three tracks coming together and played as a multi-track composition is determined by one's own and others' interaction with the superstructure.

Blip is one in a series of drawing machines. Programmed into the machine are 25 different signatures of a heartbeat as measured by an ECG monitor. There is the possibility of a "blip" being marked on the glass surface every five minutes.

At the end of each day the glass is wiped clean of its drawing and life begins again.

Ask what it means and Bulloch explains "perhaps the subject is something like 'the act of viewing is not passive'". It's a statement which sums up the challenge of contemporary art.

ÖйúAƬ

Cornelia Parker (b.1956) also makes use of the aura associated with museum displays in presenting her work. In Twenty Years of Tarnish (wedding presents) the material that commemorates 20 years of marriage is the residue of tarnish that has accumulated on two silver-plated wine goblets.

Parker takes everyday souvenirs invested with memories and nominates them as art. For Parker, a postgraduate of Reading University, the key to this activity is to retain the experience associated with the object while avoiding turning the object into a monument standing in the place of that experience. The poetic titles and information she also uses play as great a role as the object itself.

Parker refers to the pieces in the Turner show as "anti-drawings". Much like the debris she finds and uses, the visible form of these anti-drawings comes about largely through chance, as in Parker's central installation in the show, Mass (Colder Darker Matter) (above right). While on a residency in Texas, USA Parker learned that a Baptist church had been struck by lightning. She collected the charred remains and reconfigured them in an exploded view suspended from the ceiling of the gallery. The porous mass of this piece is loaded with connotations - linguistic and cultural - that stem more from the vitality of the original material and its original environment than from Parker's hand.

ÖйúAƬ

She is also fascinated with childlike measurements - such as how many St. Paul's Cathedrals equal the height of Everest or can you measure time by the growth of your hair? Such equations put measurements into the context of lived experience.

Gillian Wearing (b.1963) took her postgraduate art degree at Goldsmiths College in 1990. "Goldsmiths was the first college to use a system that says this isn't a painting department and this isn't a sculpture department and you're free to explore values in other media. Art education should allow you to experiment." Wearing's studio is the street. She uses photography and video to explore the individual's identity, often blurring lines between private and public. Her most powerful work takes on the dynamics of human relationships. Much of this work has an unrelenting quality as it resists taking sides in subjective confessions or providing a moral voice. Sacha and Mom (below, right) is a video that depicts the emotional tension between a mother and daughter, moving from smiles, laughs and touching kindness to sheer physical violence and back again. That the piece may be disturbing to an audience by now numbed to violent scenes in film and television highlights the power of Wearing's craft. The video is shown on a large screen in a small, dark room that recreates a domestic setting. She breaks the narrative code that we expect in such a setting by showing the video in reverse. The effect of playing this highly choreographed scene backwards has a greater impact on the soundtrack than on the video. Rather than hearing the coos, grunts, whimpers and wails exchanged by Sacha and her Mom one hears the equalised register of guttural, almost animalistic, raw emotion.

Wearing's second installation is another video, 60 Minutes Silence (above). This turns on expectations drawn from the conventions of the photographic portrait. Wearing asked 26 policemen and women to sit still for the camera. As time passes this frozen group image slowly breaks down, becoming a real-time team photo made up of the faces, shifts, and fidgets of each sitter.

The Turner Prize exhibition is at the Tate Gallery until January 18, 1998.

ÖйúAƬ