Which is better way to criticize an employee? (a) in absence (b) in presence of alone (c) in presence of whole.

To criticize an employee it is wise to criticize and rectify in presence of alone of the employee.Otherwise the employe may become mentally and socially sick!

Employees in your offices are all in adult ,qualified and they all have social prestige.During work ,unfortunately some of them do wrong job and so office administrator need to rectify them by criticizing about that wrong work.But, it is always to maintain the criticism in presence of that employee alone.

The suggested approach is alone with the employee.
It's important to always preserve the employee's dignity in the work environment.
Critising an employee can cause him/her to resent what can be perceived as a lack of respect.
When meeting with the employee, use the time to provideconstructive feedback, understand the employee's reasoning to why he/she did what they did and work towards a solution that fits both parties in terms of future behavior.

If necessary then it must be in presence of alone only.

Alone with the employee.
Focus using the time to evaluate and assess the worker rather than criticize as criticising offends and puts the employee on the defensive.
See the time as an opportunity for you both to grow and move on as a team

(b) in presence of alone Never chastise anybody in front of their co-workers Remember that old adage about praise publicly, criticize privately? The quickest way to lose your staff is to embarrass them in front of their fellow staffers.
It doesn’t matter if you are right or wrong; just don’t do it.
Would you want to be embarrassed by your boss in front of your peers? No.
So don’t do it to your employees.

In presence of alone

Yes, alone with the employee but always listen to what he/she has to say first and then you decide what the best solution is.

Hi - best deal would be to talk to him alone, it is called professionalism, we should respect each other, make him realize where he has gone wrong, if it still continues than ceratin steps have to be taken,

(b) in presence of alon.
It provides a positive approach to employee for his organization.
It Shows been take care of which develops employee's productivity for company.
Moreover must let him explain for his actions and then to understand reasoning behind why he did so then guide him/her accordingly. 
  

In fact the situation plays a good role in crticizm of an employee.
We must have the logical judgeement rather than emotions.
But the general inclination is to the (b) choice, namely alone.
Again some offends might require the in-public critizm so that other workers learn the lesson.