Part III : How to Conduct SEA?
SEA Methodologies and their Applications in Hong Kong


Methods

Remarks

Applications in Hong Kong
     
(VII) Multiple Attribute Analysis (MAA)
  • Aims to improve decision-making by making choices about conflicting or multiple objectives explicit and rational.
  • Display trade-off among criteria.
  • Use of weight and rating systems
  • Displayed in matrix display systems, diamond model, or value path.
  • Avoid a need for producing single summary values or indices that are supposed to capture different environmental dimensions.
  • Tend to have significant disagreements between methods as well as disagreement among individuals.
  • Purpose is not to come up with one answer but forces people to think about the problems at hand.


  • MAA is a popular methodology for proponents and consultants in Hong Kong. However, there is a general tendency that instead of making the decision-making transparent and forces users to think, it often ends up with the opposite results where the reasons are buried and decisions are based on the final scores.
  • The final scores, derived by assigning and adding up scores, with or without weighting, based on different environmental aspects (e.g. noise, ecology, water and so forth) aims to provide a quantitative representation of the proposals’ overall performance. This type of methodology must be used with caution as the approach is subjective and can be methodologically unsound. It can tend to hide the major issues which might not be reflected properly by final scores. However, this technique can, if used properly, provide a useful, quantitative, transparent and repeatable means to balance competing and disparate issues. As long as the shortfalls are recognized such methods can be useful, particularly in sensitivity analysis.
  • Moreover, qualitative information, such as rankings, have also been subject to various data manipulation as if they were quantitative information. This is methodologically flawed.
  • SEA in Hong Kong would try to make the environmental implications of a proposal and its alternatives explicit.
  • If MAA is used, it tends to use matrix display system as far as possible (e.g. SEA for the Landfill Extension Study and avoid adding up scores assigned to environmental objectives with scores from the other objectives, a practice that would lead to over-relying on the final score, and lack of transparency for decision-making.