Funding the collection of knowledge from a wide range of actors

Many research projects when working with non-academics do not fund particaption directly but rather use the apporach that land managers will attend and provide knowledge assuming payment is in the form of the new knowledge that they (land managers) will obtain from collaboration with researchers. This works well for the ellite land managers who can afford to attend workshops/meeting etc and consequently becasue only a narrow range of land managers contribute knowledge to the researchers the results are often baised - but the narrow representation of land managers is not is documented and it would appear that sometimes researchers are unaware of the problem.