Cobb school board members will appear before the grand jury at 9:30 a.m. Friday in Marietta. Who the grand jury meets with and what topics are discussed are private until May 5, when the March-April term ends and any recommendations are released, according to the district attorney's office. School officials released notice of the meeting and said it is not unusual for the district to make presentations, which are informal and in the past have covered food services and transportation. The board has been criticized recently for voting to change the dates of the school calendar.