I don't consider myself any kind of expert here, but I can give my views of the matter. These remarks are from the perspective of academic archaeology; I'm sure that government, private, and other archaeologists have different insights and concerns.
- What are your thoughts about academics publishing books about archaeology (or other non-fiction topics), but for a general readership? Is it frowned upon by other academics (seen as a "waste of time")? And how does this relate to stage of career: should only senior/tenured professors do it, or should a young professor or even graduate student - if the opportunity arises - take a stab at it?
- And perhaps also we should consider whether the prospective author has a solid signed advance contract, or whether s/he plans to write the book and then try to pitch it to publishers - with a chance of failure.
First, my general perspective. I think that communication with a general audience is essential for archaeology (and for all scholarly disciplines). I've published some general papers (Scientific American, etc.), and I give public lectures all the time, but I have not thought too much or published anything on this kind of communication.
There has been a general prejudice against popularization within the sciences generally. Carl Sagan, whose astronomical accomplishments were significant (even without his work on extra-terrestrial intelligence), was consistently nominated but voted down for membership in the National Academy of Sciences. Margaret Mead is still dumped on as a "popularizer," not a serious researcher. Is Brian Fagan considered a serious archaeologist, or just a mere textbook author? I don't know how common this attitude is today, but I do think it lingers. My guess is that many archaeologists and others still think that popularization is not serious work, and should be valued less than research and professional publication. Few will admit that today, since there is a big push for communicating the results of science, both within archaeology ( see the publications and lectures of Jerry Sabloff), and in many educational institutions. But if academic archaeologists really think this is important, why aren't more of us doing it?
I think that career stage is definitely relevant here. Once someone has tenure, it provides the freedom to do things like popularization. If a junior scholar were to write a popular archaeology book, I don't think it would be evaluated negatively in absolute terms, but it would definitely be discounted in relative terms. For example, say I am chairing a search committee for a junior scholar. If person A has published a popular book or some magazine articles, that would be seen, by itself, as a positive attribute. However, if person A has a very popular book plus one journal article, and person B has five articles in top journals but no popular works, person B would almost certainly be ranked higher. A department can't risk pushing someone whose scholarly professional research is less than stellar, since their choice could be declined at a higher level (with various possible negative consequences). This would go for tenure decisions also.
I didn't write my textbook, The Aztecs, until I had tenure. In addition to the factors mentioned above, senior scholars have the advantage of greater experience and perspective, which can benefit popularization. On the other hand, junior scholars may have more energy and passion, and if they are in the midst of relevant fieldwork, this can be a big advantage for the public. The major advice is usually to tell a story that is interesting and attention-grabbing, and junior scholars have some advantages here.
As to the issue of having a contract in advance, I'm not sure how much difference this makes. Many academics pay no attention to contracts - they sign them, and then ignore the dates or terms (or even the book project itself). Others stick to them religiously. Someone with more experience and savvy in book publishing can probably give better advice (I always start with Beth Luey's Handbook for Academic Authors). One of the main benefits I've seen from contracts is that it makes an unfinished book look more "real," more liable to be completed, when listed in a CV.
I'm not sure if this is very helpful. For a grad student or junior scholar, I would avoid large popularization projects unless one is very well organized and very productive (so that one can maintain scholarly research and publications at the same time). Perhaps one could start with smaller projects - magazine articles and the like - and then worry about bigger projects later.