performance and appraisal

In many organizations, this is the time of year for appraisals and/or performance reviews.
Which is the prime function of these : is it to appraise and assess realistically how a person is doing, give them feedback on their performance over the year, and plan for their future development - or is it to decide on their bonus or possible promotion?

The two strands are in come cases incompatible, because of the climate each one engenders. In the first case, it's essential that both parties are honest and sincere, looking for ways for the staff member to develop given their potential strengths and weaknesses. In the second, the staff member is surely going to present the best possible case they can, especially of a bonus or a raise is in the wind. Because of this, in some organizations there are two separate meetings, one to consider development and one to consider rewards. In my experience of helping with the process and running workshops form appraisers and appraisees, it's often a complicated process however well it's planned and organised