  def self.add_statistics_group(group_id)

    yaml = Research.get_config_yaml

    yaml = Hash.new if yaml.nil?

    if yaml[:statistics].nil?
      yaml[:statistics] = Hash.new
    end

    groups = yaml[:statistics][:groups]

    if groups.nil?

      yaml[:statistics][:groups] = group_id
      ary = [group_id.to_s]

    else

      ary = groups.split('|')
      ary << group_id

      ary.compact!
      ary.delete ''

      yaml[:statistics][:groups] = ary.join('|')
    end

    Research.save_config_yaml yaml

    return ary
  end