The essence of wiki working is, that certain approaches are key. Approaches (or their lack) aren't the same as expertize (or its lack).
If given the choice of an expert who could not show good editorial approaches, or a good editor with the right approaches who lacked specific topic expertize, then for this project, choose the latter, not the expert. Why? Many reasons:
- The expert (in such a scenario) may have his own foibles and bias, or unwillingness to hear others, or non-neutral stance
- The expert doesn't know how to collaborate, or work with others in a mass edited project. As a liability he may drive others off and absorb immense time and harm the communal fabric. We get one perfect article (only we don't know if it's biased because every community dialog about it descends into argument and name calling) and not a lot more.
- The non-expert with good approaches will listen to others, consider the views, research them and check the details. They may not know, but they know how to examine others' work and check facts. They foster others to work with them and as a community the work gets done to a high standard even so.
Part of Wikipedia is that although we want high quality, we aren't a cutting edge academic source. We'd like to have some of that, but it's not (as I understand it) our actual core goal.
If we're assessing what kind of editor can be broadly trusted to work on all kinds of difficult articles unsupervized and do so in a proper way (as this thread considers), then the qualities I've outlined will get you that person, and fairly high quality (though not cutting edge) writing. A PhD won't.
I agree, but let's not call them 'experts' when in fact they're rather 'good editors'. I like the idea to create some kind of special user status whenever an editor reaches the requirements you mentioned (06:09, 27 November 2009). What do you think about quality revisions though? It's also a way of showing the reader how the best editors rate the quality of an article.