I am delighted by the latest rise in the Radio 3 listening figures, which now stand at 10m when expressed on a Standard Listener Equivalent (SLE) basis.

The SLE, also known as Mandelson’s Measure, is a composite profile of a standard radio listener and is compiled from various socio-economic and other data. When listeners’ profiles differ from the SLE profile, scaling factors are constructed. For a given profile or characteristic, the scalar is found by dividing the relevant SLE quantitative proxy by the corresponding listener measure. These are then used to adjust the listening figures so that they are SLE-compatible.

For example, research has shown that an SLE listener is 6’ tall while Radio 3 listeners’ average height is 5.5 feet. Thus the SLE height scalar for Radio 3 listening figures would be 1.09 (6 divided by 5.5). So a raw group of 100 listeners would translate into 109 SLE listeners. Similarly, the preponderance of snippets and chatty presenters on Radio 3 suggests that the attention spans of the station’s listeners are lower than the SLE attention span, thereby requiring the attention span scaling factor to be greater than unity.

Care is needed to ensure that figures are not distorted. A classic example is provided by the Adverse Compensation Effect (ACE) which arises when a particular listener characteristic measure is greater than its SLE value. This would result in SLE scalars of between 0 and 1 and would thus cause SLE listening figures to fall below the unadjusted listening figures.

I have produced a technical paper which explains this method in greater detail. Unfortunately, for what I can only assume were reasons motivated by professional jealousy, the paper was rejected outright by referees acting for the Journal of the Royal Statistical Society. However, I am pleased to say that an edited version appears in today’s Daily Sport – underneath the story about Madonna moving to Lewisham.

I am also pleased to say that the value of a BBC station controller’s bonus is now linked to the station’s SLE-adjusted listening figures.

Roger Wright
Monaco