# File app/models/smerf_group.rb, line 54
  def validate
    # Decode the raw data
    decode_data()
    # Validate all fields present
    errors = validate_object_fields()
    # Process question for this group
    @question_objects = nil
    if (!@questions.nil? and !@questions.empty?)
      # Process and validate questions 
      @question_objects = Array.new
      errors += validate_sub_objects(SmerfQuestion, 
          @questions, "sort_order", @question_objects)
    end    
    
    # Clear data no longer required, this will reduce the amount of data 
    # saved to the DB
    cleanup()
    remove_instance_variable(:@questions) 
    
    return errors
  end