The Investigation On The Students' Ability Of Chemical Conjecture And Hypothesis For Senior High School At Present Stage

The cultivating students'ability of scientific inquiry is a median process and formative goal of cultivating students'scientific literacy. The ability of scientific inquiry is an comprehensive capability, it consists of eight capabilities like problem posing, conjectures and hypothesis, plan making, experiment, proof collecting, explanation and conclusion, reflection and the appraise, expression and communication. Among them, conjectures and hypothesis is a core factor. The ability of conjectures and hypothesis is also a comprehensive capability. On the basis of consulting various home and abroad literature and primary investigation, we fix on four indices as the level of this ability which are the ability of receiving facts and raising hypothesis, advancing various hypotheses related to the question, giving reasonable explanation and raising high-quality hypothesis. Owing to extensively research, according to these indices and basic evaluation theory, combing the suggestions from experts and the teachers and students in middle school, the PTA inventory is developed for evaluating students'ability of conjectures and hypothesis in chemistry. This questionnaire contains three items, the former two is to investigation students'ability of conjectures and hypothesis, while the third one is to survey the strategy of conjectures and hypothesis when students deal with the counter-example. Through analyzing the validity and reliability of the former two items, it can reflect this ability effectively and its factor, the investigation is valid and reliable. 801students were investigated who come from two key and two common senior high school both in city and country. We researched thirteen classes which in grade one and grade two, excepting key school in city involves all three grades. In addition, interview is used. Through investigation and interview, it reaches the following conclusions: 1.At present, the whole level of middle school students'ability of conjectures and hypothesis is weak. The main causes are as follows: (1).The scores of the ability of posing various hypotheses related to questions, and raising high-quality hypothesis and giving reasonable explanation are not high, the general average score does not pass 5.5(the full mark is 10). Especially, the score of giving reasonable explanation lower, average score is no more than 0.8(the full mark is 3). (2).The major students'ability of conjecture and hypothesis is at the low or lower level. (3).With the strategy of "counter example", most students remain primary theory, just only a few can change it. It shows that students are lack of the ability of Critical thinking and creative thinking. It is also important evidence that students'ability of conjecture and hypothesis is weak. 2.Seeing from the whole situation, the senior middle school students'ability in chemistry conjecture and hypothesis has no relation to type of school. Ability of conjecture and hypothesis in key school is a little higher than that in common school. But there is no obvious difference between them. 3.In the same semester, students'ability of chemistry conjecture and hypothesis is no obvious difference among various grade. 4.In accordance with ranking analysing, the percentage of students'ability of conjecture and hypothesis ranking A (strongest) and (stronger) in key school is higher than that in common school. But it shows no difference among different grade in the same school. 5. Students can not pose hypothesis to essence of the question, improper analogy and knowledge structure and the unscientific methods of conjecture and hypothesis, lack of cognition on essence of chemical reaction, lack of dispersive thinking capability and critical thinking capability are the reason that leads to their ability at a low level. 6.The ability of conjecture and hypothesis is not only relate to students'knowledge, but also to the learning environment. Environment of Loose and freeness and inquiry teaching with specific aims,open and good at oppugning teacher are advantage for cultivating ability of conjecture and hypothesis. This paper preliminarily investigated the students'ability of chemistry conjecture and hypothesis in senior high school. With this result, combining my experience, this suggestions as follows are put up for offering some references to cultivate and to improve the ability of conjecture and hypothesis in chemistry teaching. 1.Strengthen teachers'inquiry teaching training, change teachers'knowledge views. 2.Form the habit of explanation and self-explanation 3.Facing former conception, fostering the critical thinking ability4.Reinforce the teaching used the method of conjecture and hypothesis 5.Strengthen dispersive thinking teaching 6.Reinforce the teaching on essence of chemical reaction. 7.Reinforce cooperative leaning.