Doctor Who: Nightmare in Silver. had an Appreciation Index (AI) of 84.
The Appreciation Index or AI is a measure of how much the audience enjoyed the programme. The score, out of a hundred, is compiled by a specially selected panel of around 5,000 people who go online and rate and comment on programmes.
This AI figure is slightly lower than the previous three episodes, but it is in line with The Rings of Akhaten and Cold War.