"Thats all very well," said my partner last Sunday, putting aside my efforts at TV criticism with an air of slight exasperation, "but what readers want to know is whether a programme is any good or not." "That,"

I objected, "may be important in, say, theatre reviews, where a decision about a substantial outlay on tickets could depend on what a critic writes. But in television one is writing about something that has already happened. There is no such dependent action." (We always talk like this, while the children are watching cartoons.)

She was not mollified. I had missed the point, she told me. Those who had seen the programme would be seeking confirmation of their views about it (or a good unilateral row - the paper thrown down with an uncomplimentary oath); those who hadn't would at least know what everyone else was talking about and - if necessary - be able to use the review to pretend that they had indeed been in their living rooms when this or that piece of TV history was being made.

There is no good defence to the charge that one fails to understand human nature; and for someone like me, who spends much of his time speaking to journalists and politicians, it is all too likely to be true. So this week I will not only tell you what amused or interested me about the shows I watched; I will also tell you if they were good or bad. Better, even, than that - I will mark them out of 20.

Comedy first, and coming in at 13 (and rising), is Chalk (BBC1, Thursday). As other reviwers have noted, the resemblance between this show and Fawlty Towers cannot be accidental. The central manic character (a deputy headmaster called Slatt), lives on the edge of hysteria, his ambitions and neuroses dragging him into ever deeper and more leg-crossing trouble. He has a wife he hates and a young woman who tries to help him out. Last week the school was afflicted with rats and a corpse and this week saw the Inspectors calling. So this is not derivative, this is a steal.

But it's rather a good steal. There are some very funny moments, which results from the kind of elaborate plotting seen in Fawlty Towers and One Foot in the Grave. The best of these involved the ambitious Slatt masquerading as the long-lost girlfriend of an ugly, blind, male inspector, and having to deliberate whether to give the man what used to be called a French kiss.

The very word "French" would be a term of abuse in A Perfect State (BBC1, Thursday), a new comedy that appears to have been written by that famous comedy duo, Sir James Goldsmith and Lord Tebbit. The plot itself is a cross between Local Hero and the Ealing classic Passport to Pimlico, and concerns the attempted secession of a small fishing town from the rest of the UK. But its principal characteristic is a series of asinine one- liners at the expense of Brussels bureaucrats, standard sausages, straight cucumbers and all the other Daily Mail Euro-myths. At one point a young solicitor sells secession (and gets a laugh) by stating that "with the total chaos of the Euro- pean courts we could probably get away with it!" Oh yes? Well, here's a challenge to the makers of this 5-out-of-20 comedy: exactly what chaos was this character referring to? I'll guarantee to print your reply.

Documentary now, and Cutting Edge: The Bed (C4, Monday), which purported to give us a year in the life of one bed in a Derby hospital. This was an excellent idea, undermined by the maker's desire to educate us directly about the state of the health service. So shots of patients and operations were intercut with Commons debates about the crisis in the health service, and comments from doctors and nurses about conditions and statistics. This failure of nerve diluted the potential power of the original idea, and the show failed to deliver the insights and connections that a concentration on the direct experiences of those in The Bed might have given us.

An illustration of this came with one lovely moment, when a consultant reassures a jaundice sufferer that she "will soon lose that Chinese look" - and the camera slyly pulls back to show that (sure enough) his closest colleague is a Chinese woman. This was worth a hundred shots of Stephen Dorrell debating with Harriet Harman. Let the current affairs johnnies do the stuff on health-service expenditure - documentaries exist to achive something else.

Cutting Edge gets 10 out of 20, and the ignominy of being compared to a programme that brilliantly demonstrated how this trick can be accomplished - Modern Times: Mange Tout (BBC2, Wednesday). The three intercut corners of this documentary were the labourers that grow the mangetout pea in Zimbabwe, the consumers in Britain, and the man from Tesco, whose mission is to give the consumers what they want, whether they know they want it or not.

Centre-stage was Tescoman's visit to the mangetout farm, where - in our name - he capriciously bullied and chivvied the farmers into producing standard-size mangetout for as little as possible. But, instead of waking up next morning to discover a pike where his body once was, this jargon- spouting specimen of modern management was feted by the children of an area dependent on Tesco's contract with the local producers, singing "up the valley, down the mountain, Tesco is our dear friend".

The Zimbabweans, who were all called names like Blessing and Memory, spoke of their hopes and hardships in beautiful, lyrical English. But cut into their testimony was a Home Counties dinner party that could have been scripted by a playwright. Here the touts mangeurs - middle class, middle-aged, articulate men - pontificated about the third world, with an effortless arrogance matched only by their incapacity to allow the women (generally more thoughtful) to intervene. The point was not that these men were particularly dreadful in their facile adumbration of the general laws of nature (the "naturalness" of exploitation, survival of the fittest, the blessed state of having few possessions, etc), but that they were so like us - only a tiny bit more so.

Nor were they entirely wrong in their tongue pictures of how the world works. Should we stop eating the mangetout pea because we disapprove of Tesco's bullying - in which case Blessing and Memory suffer? Or should we go on buying, thus vindicating Tescoman's trading philosophy?

And these are real macro questions. As a non-didactic exploration of the relationships between the developed and developing worlds - told through real people - this documentary was a classic. Certainly an 18 - and perhaps a 19.

Chat-shows next. And a 12 for the crinkly Aussie, who returned in the Clive James Show (ITV, Sunday). "Tight" would be far too loose and baggy a word for this completely nailed-down production, in which Jack Dee, Mia Farrow, Liam Neeson and Samantha Fox each had their three minutes, 35 seconds in order to repeat the jokes agreed with the producers the week before. Not much was left to chance.

There were, however some benefits. Like the hilarious moment - taken from a US version of What's My Line - when blindfolded panellists - including Farrow's new (much older) husband, Frank Sinatra - had to guess what Mia's profession was. "Tell me," asked one of the other panellists, "have you ever performed with Frank Sinatra?"

The opposite of the Clive James format might be to interview Jane Seymour, say, on the set of Dr Quinn: Medicine Woman, while on horseback. Or Lisa Kudrow from Friends, on top of a London open-topped double-decker, surrounded by obligingly mad-looking Japanese tourists.

And that, of course, is what happened in Ruby Wax Meets ... (BBC1, Monday), a show which - at its best - subverts the world of agents, negotiations and anodyne questions. As it happens this was Wax at her best - lacking the affectation of her encounters with Fergie or Tom Hanks, and performed with that faux naivete that so destroys the outer shell of a "star". I particularly liked the moment when the grumpy Kudrow, asked what she thought of London, replied grudgingly that she "kinda thought it would be older". "What, thatched?" Ruby shot back. That was genuine quick wit, and needed no script; 15 for Ruby.

So there you are. Now you know what is good and what isn't. Happy now? It only remains for me to sit back and watch the audience for A Perfect State wane, and that for Ruby Wax, er, wax. As if.