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If you need to be persuasive, you need to know this secret.  It’s how people who influence without authority improve their effectiveness.  The secret is … character trumps emotion trumps logic.  If you win the heart, the mind follows.  On the other hand, if you win the mind, the heart doesn’t always follow.  For an example of character, think about the impact of the right people in the room asking the right questions. 
When you know this secret, it all makes sense.  You didn’t need more data …

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Whenever I take on a project, one of the first things I do is look at the system.  If I know the system I’m in, I can produce more effective results.  To figure out the system, I try to map out the context, flows of work, key events, and who does what.  
With or Against the SystemOnce I have a map of the system, I have a bird’s-eye view of how to get leverage.  I can then either try to get results by working …

If you need to interview people, what are the key questions to ask when you’re interviewing someone?  In How to Run Successful Projects III: The Silver Bullet (3rd Edition), Fergus O’Connell suggests using three basic questions during the interview to help you evaluate your candidates.
3 Questions to Ask When You Interview
The three questions that O’Connell suggests are:

What have you done?
What do you want to do?
What are you like?

What Have You Done?
The question tells you about the candidates past experience and qualifications.  O’Connell says you can find out more on this …