I t is one of the most elementary tenets of scientific research that a well-designed experiment should only contain one variable. If you're testing for the effect of a particular substance you have to be sure that its presence or absence is the only thing that changes between tests.

By Jonathon Romney Shot like a war film, this scorching expose of the brutalities of organised crime in Naples has no huggable heroes or happy endings Film Gomorrah Matteo Garrone 137 MINS, 15 There's only one moment in the new Italian film Gomorrah that resembles the gangster movie as we know it.

FILMS OF THE WEEK GOMORRAH (15) Matteo Garrone (136 mins) **** STARRING Salvatore Abruzzese, Simone Sacchettino MIRRORS (15) Alexandre Aja (110 mins) * STARRING Kiefer Sutherland, Amy Smart, Paula Patton Matteo Garrone's remarkable film Gomorrah is about a society living in fear.

By Geoffrey Macnab As a Mafia war rages on the streets of southern Italy, a brave new film lays bare the grim reality of 'La Cosa Nostra'. By Geoffrey Macnab How do you portray the Mob as it really is? It's a challenge that has tested film-makers since the earliest days of the silent movie era.

World in brief ROME Italy's film board has picked Gomorra, Matteo Garrone's study of the criminal underworld in Naples, as its entry for best foreign language film at the Academy Awards. Gomorra won second place at the Cannes Film Festival this spring.