efforts to organize a group of employees may begin by employee may begin by employee representatives requesting a union to visit the employees' organization and solicit members.the union itself might initiate the membership drive, using methods as old as picket lines or as new as Facebook,Twitter, and Youtube to promote their benefits to workers.one of the important tasks at the beginning of this activity is determining which employees are eligible to vote on union representation. supervisors are excluded from union membership,so employees must be classified before they are eligible to vote in the representation election.it isn't always simple to determine who is a supervisor. the NLRB has held that an employee may be a supervisor if they act in a supervisory role 10 to 15 percent of the time. for example ,in the nursing industry,charge nurses have often been in limbo. unions claim that these individuals represent patients,like other nurses,and thus should be part of the bargaining unit. Management,on the other hand,says they exercise independent decision making in guiding the actions of other nurses actions typical of a supervisor. thus management considers them ineligible for the bargaining unit. management may want to designate as many employees as possible with supervisory responsibilities to limit the number of potential union members.