Analysis On The Reasons Of Different Assessment Results Produced By Students In The Activity Of Assessing The Same Type Evidence

This thesis centers on how students assess evidences, the results of the assessing and reasons of it. the purpose it to help teachers to cultivate students'ability to distinguish and assess evidences and use evidence to give scientific explainations. The results of this research can not only be used to guide scientific inquiry teaching directly, provide necessary theoretical basis for teachers'to carry out scientific inquiry activities effectively, but is also significant for teachers to help students using evidence effectively, establishing and evaluating scientific explanations and models. Moreover, for upgrading scientific literacy of the public, to know about the above situation will provide an important references for educators on training people's awareness of using evidence when making decisions.In this research, "conditions of balance" is chosen as the research carrier, and a questionnaire is designed for students to collect evidence, check their assumptions and assess weather the assumptions is right or not. One hundred and thirteen students from high school, graduate, and postgraduate were tested. The test consists of two parts: questionnaire and interviews. The former is to obtain the strategy used in assessing the evidence, while the latter intends to gain further understandings of thought characteristics involved in the process of assessing. The research attempts to analyze the possible causes of students'different assessment by combining assessment strategies, thought characteristics and the results of the evaluations.Three main features are found in the stage of using evidences to check up assumptions: (1)vast majority of students prove the assumption first, and then think of ways to falsify assumptions. But there are also a few testees who used falsification of evidence only, considering that there is no need to use evidence. The two kinds of students hold different opinions on how to test the evidence of misconception on the assumption. (2)different results of hypothesis testing appeared because of students'different ways to collect evidence. (3) different groups of students'ways of using falsification of evidence is quite different, and whether students can find a correct strategy will affect the students'biases directly.In the stage of checking up assumptions, students showed four different kinds of assessment results on four kinds of assessment results: using evidence, misusing of evidence, overlooking evidence, mixing evidence. As for B-type evidence assessment, differences among three groups wais not big: more than half of the students neglect such evidence. Hhowever, a minority students'assessment results wereare : B-type evidence couldan check up assumptions, which accordeds with some logical scientists'conclusion. Almost all the other students mixed this evidence, meanwhile a few students misused such evidence. Tthe C-type falsification of evidence wais misused mostly in the four different types of evidence. Tthe ratio of high school students group, graduate group, and postgraduate group is 34.37%, 25.49%, and 26.67%, respectively. Aas for D-type, aAmong the three groups , high school group and graduate group, wereare more inclined to use D-type evidence of falsification to check up assumptions with the ratios 78.13% and 78.43% respectively. Subjects in postgraduate group showed little difference between C-type and D-type and the ratio were 56.67% and 46.67%, it wais inseparable from the postgraduates'ability to find more strategies to solve problems.In the stage of assessing evidence, the students mainly used seven different assessment strategies. Strategy 1, considering from the view of whether it balanced and accorded with assumptions at the same time; Strategy 2, firstly determine whether the evidence is consistent with assumptions, if not, neglect evidence; if they met, judged whether the lever balance. If it balanced, it meaned that the evidence was confirmed evidence, if it imbalanced, then it was falsification of evidence; Strategy 3, determined the lever's balance firstly, if it imbalanced, ignored it; if balanced, then judged whether the evidence was consistent with assumptions. If it was consistent with the evidence to corroborate the evidence, not for the falsification of evidence; Strategy 4, focusd whether the assumptions (or just looked at the balance) were consistent with the evidences. If so, the evidence was confirmed evidence,or invalid evidence or falsification of evidence; Strategy 5, mixed use of the various strategies; Strategy 6, integration of belief and some type of strategy; Strategy 7, used a strategy for the assessment of evidence, but logical error appeared.The reasons why students have different preliminary results of the assessment are as follows: the appearance of four different kinds of results is primarily due to: the assessment strategies students adopted; assessment strategies can directly determine whether students can identify evidence correctly, whether students ignore, misuse and use mixedly the evidence. There are four main aspects of the performances: firstly, among seven assessment strategies students used, only one is correct, ignoring and misusing evidence happens because of wrong strategies used in the process. Secondly, strategies are stable, but the same type of evidence produced different assessment results because of logical error, which caused the situation of ignoring and misusing evidence. Thirdly,.mixed-use strategies result in a variety of assessment results when students assess the same type of evidence, sometimes it can identify certain types of evidence, but sometimes it overlooks or misuses such evidence. Fourthly, the study also indicates that: some subjects default many assumptions because of their beliefs.After the interviews, further reasons for students to have different assessment is found out. The First Class, students ignored B-type confirmed evidence. The reason is that such evidence is contrary to peoples'intuition. People are not accustomed to thinking things from the negative side by psychology assumption, which results in ignoring such evidence by most people. The second largest category is misusing and overlooking evidence or even holding correct assessment results but basis for this assessment and of strategy of the assessment are wrong. The reasons are as follows: 1. The narrow and stable concerns of information the crux of the problem can not be fully focused and people concers narrowly and stably; 2. The problem that whether the assessment strategy is correct or wrong is badly concerned. People are likely to focus just one point and can seldom consider several points even be reminded. 3. Hold some conclusion very firmly so as to coordinate with the assumptions and evidence. The third category, the results of assessment on the same types of evidence varies a lot: identification, ignorance, and mixture. The reasons are: the focused information was very prone to change and vulnerable to the impact of the provisional information. Deep-seated reasons for this phenomenon are:, lack of coordination strategies, metacognition monitoring capability is rather poor and lack of reflection.Finally, detailed discussions are made about the different results of this study and previous ones and analyses on appropriate causes are given. meanwhile, some advice is given to frontline teaching according to the results of this research.