在日常情境與科學情境中，邏輯連接詞「或」是體現選言邏輯的主要語言成分。本研究以早期研究提出之排斥或、兼容或、兼有或、等同或、所有或等五種「或」的邏輯語意，透過問卷施測分別探討臺灣學生與僑生對於在日常生活與科學情境「或」的語意理解，再比較兩者之間的差異情形，以瞭解不同日常經驗與科學知識的學生對於「或」的理解異同。本研究發現：僑生和臺灣學生在日常情境與科學情境中對於「或」的各種語意具有不同程度的理解混淆，且兩組學生對於科學情境中「或」的語意理解較為困難。最後，本研究提出語意理解策略促進學生科學語言的邏輯語意理解，並呼籲教科書作者與教師應更加關注科學語言的使用及學生對科學語言的邏輯語意理解。

The logical conjunction “or” is the most important linguistic component of realizing the disjunctive logic both in daily life contexts and in scientific contexts. Based on five logical semantics of “or” which proposed by the previous studies, this study aimed to explore Taiwanese and overseas Chinese students’ semantic understanding of the conjunction “or” in daily life context and in scientific context and to compare their difference through the questionnaire. The results found that Taiwanese students and overseas Chinese students had different understanding toward these diverse semantics of “or” between daily life context and scientific context. However, the two groups of students had difficulty in understanding the logical semantics of “or” in scientific context. Finally, this study provided some strategies to reduce the logical ambiguities of “or”, and further suggested that science textbook writers and science teachers should pay more attention to the representation of disjunctive logic in scientific language to facilitate students’ understanding of disjunctive logic in science learning.