There are third party measures and reported technical measures. Third party measures, which may rely on internal documents include databases such as KLD and Bloomberg ESG measures. Also, Trucost has completed some analyses on various aspects of corporate environmental management which used to be used for the Newsweek Green ratings. Also, there are other databases such as the TRI database for toxics releases. Finally, if you have access to many companies and their information you may wish to speak with technical people and get their actual reported performance. All of these have their problems, but could be more objective than a Likert scale which usually cannot be observed as a benchmarking type performance measure.

The scale may be dependent on the parameter under investigation. May be Likert scale for management performance. However, the other parameter may be direct one. Reduction of GHG emissions, reduction in wastage (the production related as well as others), reduction in paper work.