scope:

The viewing tests are carried out by comparison with a reference television receiver. The choice of this receiver and the number of receivers to be tested is the responsibility of the organizers of the test. The choice of the reference depends on the degree of reproducibility required and for whom the results are intended. It may be chosen from the receivers under test. The reference receiver must be described with the results, because the judgement of the panellists wil depend upon the reference receiver chosen.