Measuring Early Vocabulary Growth in Mandarin-Speaking Children: A Corpus-Based Study

本文旨在測量臺灣地區華語兒童早期詞彙成長，以語料庫為語料來源，分析兒童詞彙成長與詞彙組成。詞彙成長的測量項目為總詞彙量、各個詞類之詞頻與其所佔的比例、名詞動詞比率、相異詞比率、以及D數值。詞彙組成的測量項目為各個語義範疇和概念層次中名詞的數量。計算結果顯示詞彙在上述測量項目中呈現隨著年齡增加而發展之趨勢。 詞彙量隨年齡增長，各個詞類之詞頻與所佔比例顯示名詞與動詞較其他詞類早習得。名詞動詞所佔比例隨著年齡增加而遞減，其他詞類所佔比例則是遞增。相異詞比率表明所有年齡層的兒童皆習得較多名詞與動詞，同時也較常使用這兩個詞類。量詞和法向詞的相異詞比率遞減，表示這兩個詞類在較大的年齡層中的使用率逐漸增加。名詞動詞比率顯示出在19-24個月時有名詞偏向，之後的年齡層中則有動詞偏向。D數值的增長呈現兒童逐漸增加的詞彙多樣性。 名詞的語義範疇經分析後得知最具體、最親近兒童生活的名詞最早習得，且最常使用，如人物名稱、工具類、動物類、食物類和交通工具類。較抽象、離兒童生活較疏遠的名詞，比較晚習得且使用率較低，如數字、形狀、顏色、以及自然現象類。名詞的概念層次經分析後可知兒童最先習得基本層次詞彙，其後才是上位層次詞與下位層次詞。而習得上位層次詞與下位層次詞的時間點則因語義範疇而不同。基本層次詞的使用率較上位層次詞與下位層次詞的使用率高。 在這些測量兒童詞彙成長的計算方法中，其中幾個測量項目或許可以在後續深入研究後，成為測量詞彙成長之指標。This study aims to measure early vocabulary growth in Mandarin-speaking children from Taiwan with a corpus-based method. Children’s vocabulary growth was examined in aspects of vocabulary growth and vocabulary organization. Vocabulary growth was measured by computing vocabulary size, frequency and proportion of parts-of-speech, noun-verb ratio, type-token ratio, and D measure. Vocabulary organization was measured by computing the number of nouns in semantic categories and conceptual levels. Results of the measures showed a developmental trend with increasing ages. Vocabulary size increases with age. Frequency and proportion of lexical categories suggest that nouns and verbs were acquired before other word classes. The proportion of nouns and verbs decreases with increasing age, while that of other lexical categories increases. Type-token ratio implies that children acquired more nouns and verbs and also used them very often in all stages. The declining TTR of classifiers and modals indicate that they were used more frequently in later stages. Noun-verb ratio reveals that a weak noun bias was found in 19-24 months, and a verb bias was found in later stages. D values suggest that children’s lexicon became increasingly diverse. Analysis of semantic categories reveals that the most concrete nouns and nouns which were the closest to children’s life were acquired earlier, such as people, tools, animals, and food, and vehicles. Nouns in these categories were also used frequently. Nouns which were abstract and far away from children’s life were acquired later and used with a lower frequency, such as numerals, shapes, colors, and nouns of natural phenomena. Analysis of conceptual levels has shown that basic-level words were acquired first, followed by subordinate words and superordinate words. The timing of acquiring superordinate level and subordinate level words varies in different semantic categories. Basic-level words were used with a higher frequency than the other two levels. All of the computations about vocabulary growth and vocabulary organization in this study have revealed general developmental trends of children’s early Mandarin vocabulary. Some of the measured items may become an index of measuring of vocabulary growth after further studies