文獻指出現今許多非英語系國家要求該國大學生以原文書課本作為上課教材。然而，許多學生對於閱讀原文書一事備感壓力。本研究旨在找出造成此困擾的原因，因此針對以下面向進行探討：(a)大學課本可讀性， (b) 多少單字量可以充分理解課本內容，以及 (c) 大學課本與台灣高中六級詞彙表相符程度。工學院及商學院為本實驗主要研究對象。
本研究發現 (a) 大學課本之可讀性超過普遍台灣大學生可以獨立閱讀的能力範圍。不僅如此，(b) 若欲達到98％字彙涵蓋量，閱讀工科課本，讀者需認識8000字族，閱讀商科課本，讀者需認識5000字族。然而，這些字彙量卻遠超過普遍台灣大學生之詞彙量。本研究更發現 (c) 台灣高中六級字表中的詞彙只達到工科課本94.3%字彙涵蓋量，達到商科課本96.54%字彙涵蓋量。這些詞彙皆未達到工科、商科課本98%涵蓋量，顯示台灣大學生有必要增加其字彙量才能閱讀原文書課本。根據這些發現，本研究亦提出英語教學上之意義探討。

Studies have found that many EFL (English as Foreign Language) university students are currently assigned to read textbooks written in English. However, many of these students feel stressful reading their university textbooks written in English. The present study investigates factors contributing to this problem by (a) measuring readability of university textbooks, (b) estimating vocabulary size needed to achieve adequate comprehension, and (c) investigating the relevance of Taiwanese six-level word list to university textbooks. University textbooks used in engineering departments and in business departments are the target textbooks used in the present study.
Results show that (a) readability of university textbooks exceeds the range suitable for Taiwanese freshmen students’ current reading ability to read independently. In addition, (b) to reach 98% coverage, 8,000 word families are needed for engineering textbooks, and 5,000 word families are needed for business textbooks. However, the vocabulary sizes needed to achieve adequate comprehension are far larger than the vocabulary size of a general Taiwanese student. Last but not least, (c) words in the Taiwanese six-level word list only provide 94.3% coverage in engineering textbooks, and provide 96.54% coverage in business textbooks. These words are insufficient to provide 98% coverage in both textbooks, implying that Taiwanese students should improve their vocabulary in order to achieve adequate comprehension of university textbooks. Based on these findings, pedagogical implications have also been proposed.

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