Eric Jackson, of forbes.com, shared a piece of groundbreaking advice he was given in regards to hiring.  You will find article after article, page after page of interviewing advice that often contradicts other articles.  The simple fact is, there is no “right way” to interview a candidate.  There are research-supported ways, but science itself refers to supported ideas as “theories” rather than “fact.”
The advice Jackson recalls, in the article “The Best Advice I’ve Ever Received About Hiring Talent,” refers to the caliber of candidates to hire.  Coming from the managing partner of a large hedge fund firm, he strongly believes hiring what is known as an “A” players (overachiever, consummate professional, strong tenures, glowing results, etc) will create a stronger company.  He believes that these “A” players will hire equally as strong professionals for their team, whereas “B” players might be tempted to hire “C” players to avoid their job being threatened by the “A” player below them.
An executive search firm will help you identify and attract these “A” players in your market place to your organization.