教科書開放使用審定本後，在出版業者製作教科書或學校選用教 科書方面，皆需要一個較客觀、簡便的評估工具。國外廣泛採用適讀 性作為評估教材之工具，但是臺灣鮮少針對國民小學教科書做適讀性 評估。本研究欲探究目前通過審定之各版本國民小學英語教科書的適 讀性，針對公式評估之結果，找出可直接適用於臺灣之國民小學英語 教科書的適讀性公式。藉助Fryinator 適讀性軟體分析變數值，並套用 Flesch 公式、Fog 指數、Flesch-Kincaid 公式、SMOG 公式4 個有效公 式及Fry 適讀性曲線圖來檢測臺灣審定版國民小學英語教科書的適讀 性級別程度。以各版本教科書設定之難易度為標準，找出評估結果完 全符合該難易度之公式。研究結果顯示，國外常用之公式無法正確評 估臺灣國民小學英語教科書之難易度，臺灣並無符合審定標準之適讀 性公式，故建置一套適用之公式有其必要性。

Since it became possible for textbooks to be published by private-sector publishers and be approved by the government, it has become obvious that we need more objective and simple evaluation methods not only for publishers, but also for schools. In many countries, readability is widely adopted as an evaluation criterion; however in Taiwan, the elementary school English textbooks are rarely evaluated according to readability. The present research examines the readability of different versions of elementary school English textbooks. The main purpose is to find a readability formula that can be used to evaluate elementary school English textbooks in Taiwan. In doing so, Fryinator readability software was employed to analyze variables, and four effective formulas (Flesch Reading Ease, Fog index , Flesch-Kincaid readability formula, and SMOG formula) were used to test grade level readability. By comparing the difficulty scale proclaimed by each textbook, it's expected that a formula can be used to account for evaluation results. The results show that the formulas frequently used to test readability are unable to correctly evaluate the difficulty scale of the textbooks. There is no readability formula which corresponds to the textbook evaluation criterion in Taiwan, therefore, a suitable formula needs to be established to evaluate elementary school English textbooks in Taiwan.