Before you begin searching
No doubt, you are already used to doing keyword searches on the Internet. The thing you need to know about keywords in order to use them effectively on a search is that you have to match them to the keywords that would be found in the candidates web page, bio, profile or resume. Plain keywords may be the simplest form of searching but they are also the core of the search itself.
Keywords are not either seen or read by the search engine in the same way that we see or read them. To a search engine a keyword is just a string of characters. Using something like @#$#&) or 73639 or "keyword" is the same to a search engine. The search services looks for records that match the words typed, not the ideas represented by the words. It will not read the word rather it will try to match the string of characters together in its listing of indexed terms. To understand this is crucial to understanding the results returned by the engine.
Do keywords matter?
As important as keywords are, this is the area that is most often overlooked by recruiters. We normally highlight the words in the job description and start writing them in a string to create queries. The search usually does not yield good results and you go on to another search engine, directory or database. There are a lot of ways to improve your search results without having to resort to the use of Boolean operators or advanced field commands.
Different types of candidates
Some of your candidates may be methodical and logical - they may break down the technical environment where they are, in terms of process, others would be more inclined to write in more technical terms to demonstrate high proficiency. Others may be aware of search engine techniques and fill their profiles with a huge list of technical terms to draw the attention of the search engines and therefore more traffic to their profiles;
Whilst others may be more emotional and relational in their approach, and would be more concerned with the experience and the results: best-performing, highest achievement, fastest time etc...
Having said this, it is important to realize that just as people may write their profiles with different motivations, they also may have diverse levels of understanding as to how the search engines work. They may write in a style that shows that they are unaware of how search engines are utilized and not grow in their volume of traffic. Others may write the ideal and informative profile, but without utilizing web techniques to draw you to the profile they too do not receive the desired traffic volume. Then there are a few who would be savvy enough to not only write a well written profile but to place it on the web in a way that it would be easily found.
Where do we begin?
In order for us to find anyone on the web we need to uncover what their purpose was for placing their information on the web. We need to know as much as we can about our potential candidates, and use keywords that reveal the precise information. Search engines, hiring managers and prospective candidates all describe things in different ways. The words you use in your search may be very different from the words your prospective candidates use. For example, if I were looking for an Oracle DBA, using the keywords "Oracle DBA" I would miss a large number of promising candidates. Yes, some might use DBA on their profiles but some would not. A large number of candidates would actually write it all out as "Database Administrator". Also, what if the candidate had been given a different title by the company he works at, maybe he is "Head Geek", or Database SME, or Database Consultant.
Before you select keywords, start by considering your potential candidates motivations and intent. What are they trying to accomplish by having their information on the web? Who are they presenting it to? Use these questions to start a list of keywords to research.