Wikipedia:Contribute where qualified
By its very nature as the biggest and most diverse encyclopedic informational resource ever written, Wikipedia is produced by thousands of contributors with widely different backgrounds, knowledge, and motivations. Professors with PhDs, High school students, bureaucrats, teachers, grad students, retirees, and so on, all contribute to the project. Wikipedia is not, could not be, and should not be written by just a few people – it needs diversity of views in order to achieve neutrality; diversity of knowledge to achieve accurate information; and diversity of access to resources, to achieve verifiability.
Contribute to Wikipedia only within your own field of knowledge, or, if you post on discussion pages or other non-article venues that fall outside your own body of knowledge, note this clearly and visibly: "Not trained in nuclear physics, but this section on reactor meltdown seems like it has some contradictions". Never claim to know someone or something when you don't, and never claim to be someone or something that you aren't.
Contributing where qualified is simply good practice, demonstrates responsibility, and helps to develop accuracy on Wikipedia in all its forms – accuracy to create a better, more reliable resource for the free use of all the world's people. Contribution does not refer only to contribution to articles; it also refers to participation on discussion pages and other non-article venues.
KNOW ABOUT IT, WRITE ABOUT IT
DON'T KNOW ABOUT IT? LEARN ABOUT THE TOPIC USING SECONDARY AND TERTIARY SOURCES, AND THEN WRITE ABOUT IT
One of the strengths of Wikipedia is that articles get proofread and edited by people from outside the specific domain of knowledge. A science article gets proofread by people with a background in English Literature and Philosophy. A Philosophy article gets proofread by people trained as scientists. Just because a person has a PhD in physics, it doesn't mean that she is a good writer of generalist-level articles for non-specialists. Even an expert in English Literature might make lapses of logic in an article, or accidentally add a non sequitor. An international expert on history might make references to a certain cultural group that are widely deemed, by the community of Wikipedia editors, to be offensive.
This proofreading and editing by non-specialists might lead to the simplification of an article about a very specialized and complex topic. If an article on Quantum Physics that was written by a PhD physicist gets simplified after general editors trim it and copyedit it, that is arguably a GOOD thing. Wikipedia articles are supposed to be designed for the "general reader", not a specialized sub-group, as in the case of a medical journal or a hobbyist magazine. If an article on a medical topic is written by a health sciences expert, there is a risk that it might be hard for a general reader to understand it. A general Wikipedia editor can make a lot of helpful contributions to an article which is aimed "over the heads" of general readers. A general Wikipedia editor could add in Wikilinks and "gloss" complex terms (using reliable sources).
As well, professional domains sometimes have "blind spots" which, as the name suggests, are hard to see if you are "inside" the group.
- Let us say that an international expert on setting up Nitrous Oxide boosters in racing car engines writes an article about this topic. However, as a person trained in race car engines, she may lack knowledge about chemistry, and she might make several errors in her discussion of the properties of Nitrous Oxide (e.g., how it expands, how it responds to temperature changes) that a qualified chemist would be able to correct. Even an editor with no knowledge of car engines OR chemistry would be able to correct grammar errors, improve formatting, and add WikiLinks. Yet the above argument appears to suggest that only racing car engine experts should contribute to articles on racing car engines.
- A professor of music history might be a national expert on harpsichord and organ tuning who travels the country giving classes on how to tune historical instruments. Despite her impressive knowledge about historical tuning and period instruments, if she writes an article about historical tuning, she might make errors in her discussion of the physics of sound production and pitch. A person trained in the physics of sound and pitch might be able to correct these errors. This is why university professors are increasingly doing interdisciplinary research (e.g., cognition research may include professors from neurobiology and psychology). When a professor in area X works with researchers in related fields, they can fill in the "blind spots".
Generalist Wiki-editors, be bold. If you don't know about a topic, learn about it using reliable secondary sources (e.g., university textbooks) and tertiary sources (Encyclopædia Britannica), and then contribute to articles on this topic. Bring your specialized skills--be they in copyediting, formatting, summarizing, etc.--to bear on articles outside of your area of expertise.