Contemporary art is a funny business. Artists labour for hours, weeks, sometimes years to make things which don't really look like anything much, which hardly anyone understands and which nobody except their mum would want to own. Sometimes they don't even make things...they make statements or actions, or other stuff you can't hang on your wall. Are they having a laugh or what?

Art is as much about being critical as it is about being representational. Traditional artforms like painting and printmaking have been used as a form of social criticism for centuries and artists have frequently employed caricature and satire to make serious social comment. Have a look at the work of William Hogarth, Francisco de Goya and George Grosz and check out the long history of political cartoons from James Gillray in the 18th century to The Simpsons and South Park today.

The art world, ie. art colleges, museums, public and private galleries, curators, critics and collectors all exist as part of a cultural industry. Its structures, beliefs and values can be criticised like any other aspect of society, and that's exactly what many artists are doing through their work (also see Play Up and Site Specific). The Dadaists and Marcel Duchamp began the 20th century trend for art as art criticism, with work or actions which questioned 'what is art?'

David Shrigley's work isn't overtly political, but it does pose moral, philosophical and aesthetic questions and its simple, mischievous, almost child-like drawing style punctures the pretensions of Art which takes itself too seriously. Next time you're in a gallery see if anything there makes you laugh.

One definition of play is any activity undertaken for its own sake, rather than because it serves a function. Could art be described in the same way? Practical jokes and pranks do have a sort of function - to make fun. But when artists make 'jokes' about art is the humour lost on all but the elite few? Everyone knows that when you have to explain a joke, it stops being funny.

Event-based humour is hard to achieve when it's not accidental. If home video mishaps are funny it's because they take a familiar situation and throw in a measure of chaos. When the ordinary becomes extraordinary, through exaggeration, juxtaposition or ridicule then we find things funny.

Roman Signer is a Swiss artist who creates a unique form of 'slapstick' sculpture, where his performances rely more on the uncertain and accidental nature of experiments than on predictable outcomes. In this way there is no such thing as a failure. Like Shrigley much of his work is profoundly absurd, both artists taking the mundane and rendering it playful.

These two artists were featured in an exhibition called "Funny Looking" at The Photographers' Gallery in 1997, curated by Jeremy Millar. Other artists whose work you could explore in relation to jokes and humour are:

• George Macunias & Fluxus
• Chéri Samba
• Marcel Broodthaers