How do TV and radio ratings work?

A statistically significant number of viewers have agreed to their viewing habits being closely monitored over each 24-hour period. Given the known size of the total potential viewing audience — that is, the number of licences issued — it is possible to make highly precise mathematical extrapolations. As a former executive producer with ITV I obsesssed about “the overnights” — a rough analysis — before studying the eventual mathematical picture.

— Robert Randell, London SE26

TV ratings are done by a firm called AGB Nielsen, which surveys a panel representing the national demographic. My wife is a panel member and was originally selected at random from the telephone directory. We have small boxes attached to each of our television sets and a zapper for each box with the names of all the family members included. We just press our own button when we start to watch TV and again when we stop. There is a facility for guests, noting gender and age range (split into 12 bands). AGBN downloads the data each night with a silent telephone call. The system is funded by the TV companies, which get not only viewing figures but a detailed age and gender breakdown and information on whether the TV is being used for programmes, DVD, video, games or text.

— Edward Green, Lichfield, Staffordshire

I was once on a TV panel. The astonishing thing is how small the sample is, yet it satisfies two opposing forces: TV stations want figures as high as possible, while the advertisers want figures, not so much low, but realistic. I worked out that every time I switched on the telly, changed channels, used the video and switched off, about 5,000 people in the country were doing precisely the same. This gives rise to my Rule of One Thousand. The more I stand and stare, the more convinced I am that humanity has just a thousand basic blueprints which nature churns out endlessly. We know from our DNA that we are all descended from just a thousand people, survivors of some global catastrophe. We also know that just a thousand carefully selected people will tell the pollsters precisely how the nation is thinking. And so it is with telly and radio.

And all the while you thought you were unique, eh?

— Huw Beynon, Llandeilo, Carms

We immediately know the origin of a man called Taff, Paddy or Jock. Is there a similar word for Englishmen?

I have come across the term “Southron” many times in old history books as a “Scots” word for the English. In modern usage the term “Southerner” is quite likely to be used by the Scots to tag the English. The Irish and Welsh do not get the “Southron” tag. A number of less pleasant terms are also used by the Scots for the English. However, they usually have two or three words strung together and therefore they do not qualify, thankfully for the squeamish.

— Roger Griffith, Chapeltoun, Ayrshire

In the North East of Scotland an Englishman is invariably recognised as a guffy or a feb.

— A. Scott, Banffshire

There are several similar words for an Englishman. Most have four letters and cannot be printed here. John Bull may be the most polite.

— Ciaran Goggins, Belfast

Why do we use the 24-hour clock for our railway and airline timetables but not for anything else?

We use the 24-hour clock for trains, flights, military use etc because it is simple and unambiguous. Some of us use it whenever we write down a time to avoid error. Most people don’t use it because “it wasn’t invented here” and is used by “revolting foreigners”.

— Nicholas Russell, Haslingfield, Cambridgeshire

The simple answer is that this assertion is not true. Many digital clocks use the 24-hour system. The 12-hour system lingers on only because of the traditional use of clockwork clocks.

— J. R. Pope, Tisbury, Wiltshire

Why is Easter so early this year? I always thought it was the Sunday after the first full moon after March 25.

— Ida G. Staples, Houghton, Cambridgeshire

If the human race were to disappear today what would the landscape of the industrial world look like in 10, 25, 100 and 1,000 years time? What form of animal life would be dominant?

— David Turner, Whitstable, Kent

How do birds of the tit family quickly locate peanuts even though the containers are located far from their nesting places?

— Peter Hughes, Burnham, Buckinghamshire