They are interested in gaining insight, not just acting a judge and jury. Here are some tips to help ensure that advisory members have the opportunity to learn as they serve. Shift the role for the members by initiating a rule that a member will spend 5-10 hours of personal time participating in finding the answer to the question. This helps them dig deeply into the available information. They also share the responsibility for answering the question.
Advisory members are often temporary participants in complex systems.
This is especially true in government based programs. Establish terms for members and criteria for service. Make sure there are members with long tenure and knowledge of the organization and the volunteer program, but rotate people on and off on a regular schedule. Be sure there are written guidelines to outline criteria of members and tenure. Then going off the group is not a personal decision of staff, but one dictated by rules.