Evaluate potential success

 There is no use whatever trying to help people who do not help themselves. You cannot push anyone up a ladder unless he be willing to climb himself. 

–Andrew Carnegie

Based on your observations and hypotheses, consider:

• "Is the person willing and able to be helped?" Coaching works only when the coachee willingly agrees to participate.
• "Is the performance problem solvable?" Some problems are so deeply ingrained that no amount of coaching can help. How do you identify such problems? Unproductive behavior—whether it's bossiness, competitiveness, or lack of self-confidence—that manifests itself frequently and in a wide variety of situations most likely can't be improved through coaching.