本研究探討教授阿基米得原理與引導式發現教學法對學生學習浮力概念的成效。共有兩個學校6個國二班級193位學生參與研究,一間學校在台北縣市區、一間學校在桃園縣郊區。由兩位教師分別只教授課本教材(對照組)、以慣常使用的教學法但加入阿基米得原理教材(實驗A組)、使用引導式發現教學法且加入阿基米得原理教材(實驗B組)。每個班級均施以前測、後測,並蒐集學生的理化學期成績。前後測工具為研究者自行開發,經一位科學教育專家和三位國中理化科教師審查修正,前測信度α=.53,後測信度α=.71。所得資料除做描述統計,並做卡方考驗、變異數分析。研究發現學生有如下的七個迷思概念:1)單向誤用學到的浮力概念;2)只利用物體密度、體積、質量(重量)大小來判斷浮力大小,而忽略其它因素;3)只要同樣是沈體或浮體,不管物體在水中體積、液體密度如何變化,浮力就都一樣;4)沈體不受浮力;5)只注意到題目中的變化量來判斷浮力;6)物質的性質使浮力改變;7)浮力和物體與水的接觸面積有關。引導式發現教學法與融入阿基米得原理的教材對桃園縣的國中生學習浮力概念有顯著影響;但對台北縣的國中生無顯著影響。以後測成績分群,高、中、低分群學生經過教材與教法的改變後有較佳的進步。以理化學期成績分群,中、低分群學生經過教材與教法的改變後有較佳的進步。
Investigated were effects of teaching Archimedes principle and employing guided discovery pedagogy during teaching of buoyancy. One hundred and ninety-three students from six classes of two schools participated in this study. Two schools are located at Taipei county and Touyuan suburban area respectively. Six classes were assigned into three groups. For the controlled group the teaching materials within textbook were taught through didactic teaching method; for the experimental group A the Archimedes principle was taught additionally however, didactic teaching method was still applied; and for the experimental group B Archimedes principle was taught through guided discovery pedagogy. There were two teachers responsible for teaching of the three groups. All subjects completed pre- and post-test. The reliability (α) of pre- and post-test are .53 and .71 respectively. The results indicated that students had seven misconceptions as the following: 1) applied the buoyancy formula in a wrong way; 2) only thought of density, volume, and mass when judging the buoyancy; 3) no matter how liquid density and the volume of object within liquid were changed, the buoyancy of floating objects were always the same, so was the sinking object; 4) no buoyancy imposed on the sinking objects; 5) only pay attention to the variants listed in the item when estimating the buoyancy; 6) the property of objects could change buoyancy, just like salt could make buoyancy stronger or weaker; 7) the amount of area contact with liquid would change buoyancy. There was a significant difference (p<.05) in students’ understanding the buoyancy among three groups in Touyan school, however, not for students in Taipei school. Based on the post-test, all students in the experimental group B, no matter belonging to the high , middle, or low scores, had more improvement than other groups. When the grouping criteria was based on students’ physical science final scores of the semester, only middle and low scores’ students made more progress in the post-test.