RADIO / Extra ordinary: Robert Hanks on the potential pitfalls of making slice-of-life documentaries

One of the most satisfying things a radio feature can do is to act as a magnifying glass, scaling up something apparently mundane to the point where you can see how individual and strange it is. The remarkable thing about the first part of The Street (Radio 4, Fri) is the way it avoided doing this: here was an ordinary street in an ordinary town - Lister Avenue in Doncaster - which after half an hour of careful examination still seemed precisely and crushingly that. There's a symmetry here you couldn't achieve if you set out on purpose to do it.

The credit for this lies entirely with Tony Wilkinson, formerly responsible for programmes such as Wilko's Weekly in which he examined the life of communities through their local papers. For this series he acts not only as anchor-man but producer, too.

Wilko has two trademarks. One is to continue speaking his commentary over other people's recorded voices, very often editing what they say into his own statements, as with Sean the paper-boy: 'He's going to be a fireman when he grows up. And he's got a pet tarantula spider. I can see it when he's finished his round if I want.' The intention is, I guess, to create a sense of immediacy, but it makes you feel that the reporter is interposing himself between you and the subject - something accentuated by Wilko's 'my, isn't this surprising,' tone, which gives the programme an air of condescension.

His other trademark is a penchant for unconvincing generalisation: 'They like work on Lister Avenue.' The only evidence for this observation was one person saying that there were only two or three unemployed people on the street, which leaves you some way short of a work ethic. In any case, how would you back up such a sweeping thesis? You doubt that Lister Avenue can be such a homogeneous community, or that Wilko really thinks it is. This looks like being the main problem with the series - on the one hand, Wilko wants to use streets as cross- sections, which means showing them teeming with variety; and on the other, he'd like to slot everybody into neat categories.

To see how unnecessary this urge is, you only have to look at Relative Values (Radio 4, Tuesday), Michael O'Donnell's series of illustrations of the varieties of family life, now in its umpteenth series and still intriguing. O'Donnell's constant theme has been that there is no such institution as 'The Family' - that the word applies to so many structures, encompassing every permutation of sexuality, kinship, age, race, whatever, that any attempt to impose a single model is not just misguided but incoherent. The idea is mildly subversive, and wholly indisputable.

The Charnocks, who opened this run, are a mixed-race family from Manchester - Tom, Mandy, and their two sons Wesley (blond, blue-eyed) and Thomas (black). That was less interesting, as it turned out, than the fact that Tom and Mandy were divorced; and the message of this programme was that trying to work out your problems isn't always a good idea. Tom and Mandy, having married for what they both agreed were the wrong reasons, found a measure of contentment in splitting up.

If the Charnocks' story poked a few shibboleths of the right, it provided little comfort for the left. Tom, having emerged as a wife- beater, nevertheless became increasingly appealing as things progressed, admitting to his emotional inadequacies and ending up by declaring that he was really only interested in having a good time. Meanwhile Mandy, having adopted her father's Yoruba surname and taken the first name Eve, is planning to go to university, and chortled merrily about the advantages of being a black single parent. Such a blatant admission of positive discrimination is, for many people, unpalatable; but at least it had bite to it. You'd rather that than any amount of Wilko-ish blandness.