QUOTE (Don_Humpador @ Feb 5 2010, 17:47)

I've been wondering, is it possible to distinguish the amount of people who are watching BBC1 and the number of people who have pressed the red button on BBC1? I'm guessing - just guessing - that the commentary figures on 301/302 from last year were able to be counted.
Based on figures I seen last year, about 200,000 to 400,000 watched practice. Britain was a bit higher, an average of 522,000 watched the sessions. Alternative commentary options had approximately the same amount.
QUOTE (Don_Humpador @ Feb 5 2010, 17:47)

Also what counts to a "rating" - how long does someone need to be watching for it to be counted as a rating? 25% of the show? 50%? 75%?
Apologies if the following sounds complicated. Ratings are measured minute-by-minute by BARB. The minute-by-minute averages gives the 'average' rating (or viewership) for the entire programme from start duration, i.e. at 12:10 and end duration at 15:00. Let's take the following 10-minute programme, as an example, i.e. a news bulletin.
18:00 - 2.1m (19.0%)
18:01 - 2.2m (18.9%)
18:02 - 2.3m (18.4%)
18:03 - 2.4m (18.2%)
18:04 - 2.5m (18.6%)
18:05 - 2.6m (19.0%)
18:06 - 2.7m (18.8%)
18:07 - 2.8m (18.2%)
18:08 - 2.3m (15.4%)
18:09 - 1.9m (09.9%)
So say in the above, 18:00 represents the period between 18:00:00 and 18:00:59, and 18:09 represents the period 18:09:00 to 18:09:59. (which is the reason that 18:10 isn't on there, as that covers 18:10:00 to 18:10:59, which is outside of the broadcasted period). So just as an example, 2.1m people were watching between 18:00:00 and 18:00:59, which was equivalent to a 19.0% viewing share at that time. A viewing share is the 'share' of people watching at that time, which is a reason why Formula 1 usually has very high viewing shares, as it is on at a time when only 10 million people. So it may have 4.5m viewers, which is relatively low, but it'd have a 45% viewing share, which for its timeslot would be brilliant. Normally, viewing is in 5-minute portions (for whatever reason the 1-minute portion like the ones I gave above are rarely reported). Using the same example above:
18:00 - 2.3m (18.6%)
18:05 - 2.5m (16.5%)
18:00 this time represents 18:00 to 18:04:59, otherwise known as a 5-minute breakdown. Same data as above, except it has been 'merged' into 5-minute chunks (for an F1 Qualifying breakdown of a similar nature click
here). The whole broadcast from 18:00 to 18:10 would give an average of 2.4m (17.5%).
I don't know who it's actually done technically as I don't have a BARB box (whether a signal is sent at every half minute or something), I've probably gone into way to much detail there, but that's an overview of how ratings are calculated.