def normalized_log_term_frequency(document, term)
      count = document.term_count(term)
      if count > 0
        (1 + log(count)) / (1 + log(document.average_term_count))
      else
        0
      end
    end
def normalized_log_term_frequency(document, term)
      count = document.term_count(term)
      if count > 0
        (1 + log(count)) / (1 + log(document.average_term_count))
      else
        0
      end
    end
SMART L, Chisholm LOGN