Left-wing bias and inappropriate guests are common criticisms levelled at Question Time. Here, the man in charge of the show answers eight of the most frequent complaints and queries.
What is Question Time for?
Question Time is, and always has been, a popular current affairs discussion programme which aims to give people an opportunity to scrutinise directly senior politicians and others who exercise power and influence at a UK level.
It successfully appeals not just to those viewers who have a strong interest in politics, but to a wider audience, which is why it is broadcast on BBC One.
More younger people watch Question Time than any other political programme on British television.
It is an article of faith for the programme that it is driven by members of the audience - David Dimbleby, as chairman, is their champion in getting answers from the politicians and in promoting lively debate - not just among the panel, but between the panel and the studio audience.
That is also why the programme is broadcast from all round the country, not just London and the other big cities - to make sure that a broad cross-section of licence-payers have the chance to take part directly and that a diverse range of British opinion is represented in the studio audience.
How does Question Time select its panel members?
It's a surprisingly difficult and intricate process.
There are many different sorts of balances we're trying to achieve, some within a single programme, others across a whole series.
Question Time is rooted in politics and therefore has to achieve a fair and appropriate representation from the various political parties across the UK.
In normal programmes, that means Labour and the Conservatives are virtually always represented; in the majority of editions, so are the Liberal Democrats.
We keep these proportions - and those of smaller parties - under constant review, taking as our guide the level of electoral support at national level which each party enjoys.
The "non-party political" panellists primarily are chosen, we hope, to be lively and interesting and to add a different dimension of expertise or opinion.
Nevertheless, their political views are taken into account in assessing the overall balance of the panel. We speak to many potential panellists to assess their suitability.
Do you try to get political opposites/ outspoken stalwarts on the same show to play against one another?
It's not a primary objective, though we do, of course, think about what you might call the "panel dynamics" - how different personalities might play off each other.
We are looking for a range of views - if all the panellists agreed on all the issues it would be rather dull.
However, some of the most interesting programmes have been where there have been unexpected and unlikely alliances between contrasting panellists - head-to-head argument all the time also risks becoming tiresome.
Why did you move from four to five panel members?
The programme has tended to have five panellists for more than five years now - although very occasionally, with a particular combination of panellists, we may still stick to four.
One of the benefits is that we can take risks, something which a programme as well established as Question Time needs to remember.
People underestimate how daunting it can be to appear on Question Time and panellists who are younger, less experienced, less confident, can feel very exposed and "under-perform".
Having five panellists allows more flexibility and the opportunity to introduce panellists from more walks of life.
But the main impact is that it means the three party politicians are not so dominant - there is a tendency for them to speak the language of Westminster.
Having at least two non-party politicians can redress that balance and make the programme more accessible to the general audience.
What are actors and comedians doing on Question Time - don't you think it lowers the tone?
As above, we are always looking to broaden the range of people on Question Time.
We seldom have people on simply because of their prominence as actor or comedian (in fact, there have been very few comedians on across the series) - invariably there will be a strong political or other dimension to them.
For instance, Adam Rickitt, who was on recently and is famous as a Coronation Street soap star, is also on the A-list of would-be Conservative MPs.
How does Question Time select its audiences?
The short answer is: with great care.
People apply through a phone number given on the programme or via the website.
They are then questioned about their views, voting intentions, background etc, in much the same way as an opinion poll.
From that, the producers select a broad and balanced cross-section.
If, from those applying in a particular area, they feel any group or view is under-represented, they will - occasionally - contact local groups to encourage their members to apply to be in the audience.
Why are Question Time audiences always biased in favour of left-wing policies?
They are not. As indicated above, they are selected to reflect a broad range of views right across the political spectrum.
It is, however, notoriously impossible to make a judgement about the overall views of an audience based on the noise they make or the levels of applause.
It is also impossible to force people to speak in favour of a particular view, even if you know they are in the audience and hold that view.
In fact, there has been more criticism recently that the audiences "sound" anti-government.
That is not because there are not people in the audience who support the government, but, in my view, because those people are less willing to air their views in public than those who attack the government.
Five years ago, the opposite was true. This says more about the climate of British politics, than it does about the balance of the Question Time audience - these are perceptions which tend to ebb and flow.
What do you think of the interactive element of Question Time? Aren't some of the comments you publish just plain silly?
Texting to Question Time has become very popular as a very basic form of interactivity with the programme.
Only a small selection can be displayed - by their nature, they are short, reactive and to the point, rather than deep political analysis.
Texting has its own vocabulary and style.