Today my first interview on BBC Radio 4 aired – as part of the Friday afternoon programme “More or Less”: available here
I became involved in this when a producer contacted the Royal Statistical Society who fielded it out to the Statistical Ambassadors looking for a volunteer.
What started out as a very simple listener question:”What’s my chance of being called to do jury service” from a Scottish resident threw up many different quirks of the Scottish system. In order to simplify the problem, I first decided to look at the probability of receiving a citation (the equivalent of a summons); because this part of this could be treated as an essentially random process.
The Scottish Courts service helpfully provided data on the number of citations issued and also the number of jury trials in Scotland, leading to the first quirk of the Scottish system: they have 15 rather than 12 member juries. From this we could work out the probability of being cited from the Scottish electoral register [which contains some people who are ineligible for service].
I used a poisson distribution to model the probability of receiving 0 (zero) citations in a year. For ease, I assumed that this rate was approximately constant over the range of years under investigation. This may, in reality, be a bit of a stretch for the 53 years of typical eligibility, the listener in question had only 9 more years before he could opt out for age reasons. I also assumed that the chances of receiving a citation is independent year-on-year (although eligibility is definitely not independent). I also assumed that the number of trials in a catchment area was approximately proportional to the number of people on the electoral register – again, this simplification had to be made as that was all of the available data – anything deeper would have been beyond the scope of a general audience radio programme.
Last year, only 13% of those who were cited actually served on a jury in Scotland..
Because you are exempted from jury service for a period after being balloted for service (and for even longer if you actually serve on a jury), looking at the number of times a person can serve on a jury is far more complex.
As for the experience of recording the programme. All of my interactions were with a producer (who was lovely) – many emails, several phone calls and then a trip for me into BBC Bristol to record my thoughts on a decent ISDN line. The recording took about 25 minutes in total, partially because some new questions popped up during the recording, meaning that I ran some calculations on the spot! These were condensed into about a minute on the radio. Because of the format of the show, and the fact that I was prerecorded, it wasn’t nearly as stressful as I’m sure other media experiences can be [I wasn’t there to argue or provide balance against another person].
Listening back to myself was a strange experience – I definitely moderated my voice to ensure that my accent is less pronounced and also I spoke much more deliberately than usual. Perhaps this was because I was conscious that More or Less goes out to quite an international audience (it is also broadcast on the World Service).
To be decided 