本文探討光碟資料庫終端使用者之詞彙選擇決策樹與心智模型。本研究以國立臺灣大學學生為研究對象，以PsyLIT光碟資料庫為檢索系統，計有52位檢索者進行了58次檢索，產生了532個詞彙。本研究分析此532個詞彙之決策過程，產生詞彙選擇決策樹，並據此歸納出敘述語型、文內字型、敘述語傾向型和混合型等四種心智模型。

　　　　　This article analyzes the term selections and mental models of college and graduate students in National Taiwan University when they are using PsycLIT CD-ROM database. After instructions, 52 subject searches through the semester, doing 58 searches and generating 532 search terms. This article successfully identities term selection tree and four types of mental model: Descriptor Only Type, Text-word Only Type, Descriptor-oriented Type, and Mixed Type.