本研究主要目的是探討各種不同科學測量法在評量學生寫作時，使用詞彙之廣度或成熟度。研究者提出兩組寫作提示含一組記敘文，一組為論說文來引導學生在最自然的情境下完成兩篇書寫語料。研究者並發展出六種詞彙測量法及語料分析規則，將每篇語料進行分析。
本研究之對象為108名國中二年級學生：涵蓋三組語言能力不同之學生（每組36名）。研究結果發現六種詞彙廣度測量方法：總字數、總詞數、相異詞、非常用字、非常用詞，及校正過後之相異詞比例（corrected type token ratio）均可以用來區辨三組語言能力不同之學生。本研究結果亦驗證了用”字”為單位來測量詞彙廣度與用”詞”為單位，有相同的信度。
這項結果，提供了教師評量學生書寫語言中詞彙豐與否之客觀且簡易之方法。日後將繼續研究國小高年級學童及高中職學生，以驗證在其他教育階段應用之可行性；期能發展成一套簡單易行且客觀正確之詞彙廣度測量方法，以應用於鑑定書寫語言有障礙的學生。

The purpose of this study was to identify different measurements in assessing vocabulary size of Chinese written language. Two written prompts, one in the narrative mode and the other in the expository mode, were utilized to elicit two written language samples per student. 108 subjects 36 in each level of language achievement were scored in both written samples based on six various measurements.
The results indicated that six factors used to measure vocabulary size（i.e., total characters, total words, different words, mature characters, mature words, and corrected type token ratio）can bets differentiate vocabulary maturity among the groups. The findings also provided evidence that suing characters as a unit to measure the vocabulary size has the same reliability as that measure by words.
Later on, it would be valuable to conduct several studies in different grade levels in order to gain a complete picture of measuring vocabulary size in Chinese written language.