Lyric FM has been doing that very thing on Sunday nights with Bill Bryson's Divided By A Common Language, a six-part series looking at American English and how it has developed so differently from other English-speaking cultures.

The series was produced for the BBC, and it shows. That's not just because Lyric FM clearly isn't in a position to fork out for Bill Bryson's leisurely tour of America, it's because, unlike so many home-produced programmes, it's not gazing at the domestic navel. It's not about Irish culture and there are no Irish people in it . . . no property values, no hospital trolleys, no uilleann pipes, nobody's granny from Clonakilty. It's a holiday from our national preoccupation with ourselves. It's like going abroad.

Bryson's scope is massive . . . his survey of the language is examining almost every aspect of American popular culture, and he's travelling all over the United States and taking in 375 years of history along the way. At times you forget what he's supposed to be doing, but it's a pleasant enough forgetfulness.

Last week's programme looked at the westward migration that was to transform the American character forever. Once people stopped staying in one place, accents . . . along with ideas . . . became fluid and changeable, said Bryson, who himself has an unhurried, nasal twang that makes him sound as if he was brought up in the same kitchen as John Malkovich.

He amused himself a bit with the pioneers' hasty naming of places they came to along the way . . . Truth or Consequence, New Mexico; Bowlegs, Oklahoma. Then there were the names that were discreetly changed afterwards by embarrassed residents, such as Two-Tits, California, he said, pointlessly suppressing a laugh.

The subject of the move west made a welcome diversion to that of cars. "Americans made almost no significant contribution to motoring technology, " he said (and Ford drivers will surely agree), "but they made the car their own." They built all those legendary roads, such as the Lincoln Highway and the now defunct Route 66, and with them came a new, peripatetic vocabulary of diners and motels and allround rootlessness. Romantic isn't it?

Tonight's programme tackles Hollywood, and the popularisation of the American myth, and should be well worth listening to.

Another programme with a broadly roving remit is More Or Less on Radio 4.

This began as a six-part series about numbers, as figures/data/statistics have become so much used and abused in public argument. Then the BBC realised it would run and run, so it's now 'more or less' a permanent fixture on the schedule.

The new series began last week with a look at that study in the news recently which showed that giving nutritional supplements to offenders improved their behaviour. Strange but seemingly true . . .

and presenter Andrew Dilnot was careful to interrogate one of the researchers, Bernard Gesch of Oxford University, about the reliability of the findings.

Apparently there was a 26% decline in incidents ranging from violence to insolence at Aylesbury prison among inmates who took vitamin pills. Dilnot wanted to know why the British Home Office hadn't acted on this research, even though it has had the information for years. Dilnot is more the scientist than the philosopher, obviously, if he wasn't taking into account the political implications of surreptitiously modifying people's behaviour.

That item segued, neatly if unintentionally, into a piece on the 'Hawthorne effect' . . . the phenomenon whereby the very act of measuring something affects the thing being measured. People who are being studied know they are being studied, in other words. No doubt prisoners who are being studied are particularly glad of the attention.