protected void printAttributeSummary(boolean nominalPredictor, 
                                       boolean numericPredictor, 
                                       boolean stringPredictor, 
                                       boolean datePredictor, 
                                       boolean relationalPredictor, 
                                       boolean multiInstance) {
    
    String str = "";

    if (numericPredictor)
      str += "numeric";
    
    if (nominalPredictor) {
      if (str.length() > 0)
        str += " & ";
      str += "nominal";
    }
    
    if (stringPredictor) {
      if (str.length() > 0)
        str += " & ";
      str += "string";
    }
    
    if (datePredictor) {
      if (str.length() > 0)
        str += " & ";
      str += "date";
    }
    
    if (relationalPredictor) {
      if (str.length() > 0)
        str += " & ";
      str += "relational";
    }
    
    str = " (" + str + " predictors)";
    
    print(str);
  }