To make the process as transparent as possible and to avoid imposing unreasonable demands on the participants in the process the scoring methodology should be kept as simple as possible. In many cases a mark out of five is adequate to allow differentiation between the options.
Where a criterion is assessed by a quantified measure (e.g. a recycling rate) in the first instance a conversion table should be agreed in advance to convert that measure into a score as illustrated in Table 2 below.
Table 2: Recycling Rate Conversion
Additional recycling delivered by the residual waste treatment option (as % of WDA's MSW) | Score |
0 | 0 |
0.1 -1.0 | 1 |
1.1 - 2.5 | 2 |
2.6 - 4.0 | 3 |
4.0- 6.0 | 4 |
6.1 + | 5 |
Where a criterion is assessed by an unquantified qualitative judgement the parameters within which such judgements are made should be specified and documented in advance as far as possible.