本研究的目的在於經由哲理及文獻上的探討發展一個適當的科學本質概念架構，並據以發展並效化一套適切、可靠的評量工具「了解科學本質量表」(Understanding of the Nature of Science Scale,UNOS)。本研究以臺北地區(包括臺北縣、市)的高中學生為對象族群，採「分層逢機取樣」與「集群取樣」兼行的方式取樣。計抽取42個班級，於剔除無效樣本後，共得1670位樣本。 經分析主要科學本質有關工具的概念組成與架構，及參考近來科學哲學、科學史、及科學社會學的研究與發展，本研究提出一個有關科學本質的概念組成及架構；並據以發展「了解科學本質量表」及其三個分量表。三個分量表的名稱為「科學方法的本質分量表」、「科學知識的本質分量表」、與「科學事業的本質分量表」。 「了解科學本質量表(UNOS)」的信度表現可稱理想，以Cronbach α係數表示，UNOS總量表的Cronbach α係數值達0.90，三個分量表分別為0.74、0.79，及0.77。同時效度以UNOS及其三個分量表對中譯的SPI相關係數表示，其範圍為0.57~0.64，屬於可以接受的中度相關。另區別效度表示各個分量表的屬性是獨立平等的概念，支持本工具分成三個分量表的概念架構。 研究同時發現高中女生對科學本質的了解很明顯的高於男生，高中學生對科學本質的了解沒有隨年級的增加而顯著的增強，修習科學科目較多的組別(第二、三類組)對科學本質的了解顯著優於修習科學科目較少的組別(第一類組)。

　　　　　This study aimed to develop an appropriate conceptual scheme for nature of science and, accordingly, construct and validate a proper and reliable instrument for assessing the understanding of the nature of science. The target population of this study was the high school students in the Taipei area, and stratified random sampling and cluster sampling were employed. A total of 42 classes were selected, 1670 samples in the study. First of ail, efforts was concentrated on reviewing main instruments concerning the understanding of the nature of science, and recent research and development in the field of philosophy, history, and sociology of science. Then, this study proposed a scheme of conceptual structure and components. According to the scheme, the study constructed a four-point Likert scale, the Understanding of the Nature of Science (UNOS), and its three subscales, namely, the Nature of Scientific Method subscale (NSM), the Nature of Scientific Knowledge subscale (NSK), and the Nature of Scientific Enterprise subscale (NSE). The reliability of the UNOS was high. The Cronbach a coefficient was 0.90 for the whole scale, and 0.74, 0.79, and 0.77 for the three subscales. Concurrent validity of the UNOS with SPI, ranged from 0.57 to 0.64. These figures were regarded as moderate high and acceptable. Besides, discriminant validity was held in the study to support the conceptual scheme of three subscales. The results of the study showed that female students' understanding of the nature of science was significantly better than that of males. Students' understanding of the nature of science did not improve significantly along the promotion of grade in senior high schools, and students with more exposure to science courses got significantly higher understanding of the nature of science than those with less exposure.