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Weighting Method
Principal MethodName:
Expert panel
Method Description:
The panel procedure

The panel procedure used in this project was designed and executed for our project by Thomas Mettier.

Earlier [BRUNNER, 1998] had analysed the problem and some earlier attempts to use a panel for this application.

The procedure developed and executed by [METTIER 1999] exists of three steps:
1. Development of a questionnaire. This phase also contained a number of tests, in order to check if the questions were understood in a proper manner.
2. Sending out the questionnaire to 365 respondents. These respondents were all listed, or had been listed as members of the Swiss discussion platform on LCA. The questionnaire was written in
German. Members of the Eco-indicator development team were excluded.
3. Analysing the results, and reporting back to the respondents. Unfortunately only 82 questionnaires were returned (22%).
Mettier did not aim for a real statistical representative study of society, for that would need a much larger sample. His aim in this stage of the research was to get statistically significant differences
between damage categories. As we will see this aim was reached.
The questionnaire developed by Mettier contained basically five parts
• An introduction, containing a brief description of the purpose, the outline and intended application of the Eco-indicator 99 methodology, and a description of the damage categories. The latter also contained a brief description of the estimated present damage levels in Europe, in terms of the number of DALYs, the percentage of read list plant species and information on surplus energy.
This data was not obtained from the normalisation process, but from independent sources. This means they reflect the present and not the steady state damage
• Ranking. Respondents were asked to rank the damage categories in order of decreasing importance (or to state that they were equally important)
• Assigning weights. The respondents were asked to give weights directly. In that process they were also asked to what extent they used the information about the present level of the damages.
• Cultural perspectives. A number of standard questions were used to analyse to what extent the views of the respondents coincided with the basic cultural perspectives.

• Background questions, such as age, sex etc.
In the test Mettier also included some hypothetical LCA results, expressed as three damages, and asked the respondents to state which product would have the lowest overall load. These questions were removed from the questionnaire, as respondents felt they were tested if they had to answer the same
basic questions in a different way.
The detailed results are discussed in [METTIER 1999] and summarised in the annexe report but the main results will be illustrated using the mixing triangle concept, discussed above[HOFSTETTER 1999].

Literature Reference:
1. [Mettier 1999] Mettier T. : Der Vergleich von Schutzguetern - Ausgewaehlte Resultate einer Panel-Befragung,
in: Hofstetter P., Mettier T., Tietje O. (eds.), Ansaetze zum Vergleich von
Umweltschaeden, Nachbearbeitung des 9. Diskussionsforums Oekobilanzen vom 4.
Dezember 1998, ETH Zuerich).

2. [Hofstetter et al 1999] Hofstetter, P.; Braunschweig A., Mettier M., Müller-Wenk R., Tietje O.;
Dominance Analysis in the Mixing Triangle, A Graphical Decision Support Tool
for Product Comparisons, Submitted to the Journal of Industrial Ecology.
Methodological Range:
Geographical range is Europe

Temporal range 1990~2000

Weighting Factors
Category Indicator name Quantity Unit Note
DALYs (ECO-indicator/1999) 400 ECO 99 unit/DALY
PDF (ECO-indicator/1999) 400 ECO 99 unit/PDF m2 yr
Resource damage (ECO-indicator/1999) 200 ECO 99 unit/MJ