1.3科学方法
Section outline
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How do scientists obtain new knowledge?
::科学家如何获得新知识?All the information in textbooks had to come from somewhere. In the sciences, new information about the natural world is a result of scientific investigations . These investigations are shaped by the scientific method.
::在科学领域,关于自然界的新信息是科学调查的结果,这些调查是由科学方法决定的。Scientific Method
::科学方法The scientific method is a process used to investigate the unknown ( Figure ). It is the general process of a scientific investigation . This process uses evidence and testing. Scientists use the scientific method so they can find information. A common method allows all scientists to answer questions in a similar way. Scientists who use this method can reproduce another scientist's experiments .
::科学方法是一种用于调查未知情况的过程(图 )。这是科学调查的一般过程。这一过程使用证据和测试。科学家使用科学方法来获取信息。一种共同的方法可以让所有科学家以类似的方式回答问题。使用这种方法的科学家可以复制另一个科学家的实验。Almost all versions of the scientific method include the following steps, although some scientists do use slight variations.
::几乎所有科学方法的版本都包括以下步骤,尽管有些科学家确实使用微小的变异。- Make observations .
::提出意见。
- Identify a question you would like to answer based on the observation.
::找出一个您想根据观察结果回答的问题。
- Find out what is already known about your observation (research).
::了解您观察的结果( 研究) 。
- Form a hypothesis .
::形成一种假设。
- Test the hypothesis.
::测试假设。
- Analyze your results and draw conclusions .
::分析结果并得出结论。
- Communicate your results.
::传达你的结果。
Steps of a Scientific Investigation. A scientific investigation typically has these steps. Making Observations
::提出意见意见Imagine that you are a scientist. While collecting water samples at a local pond, you notice a frog with five legs instead of four ( Figure ). As you start to look around, you discover that many of the frogs have extra limbs, extra , or no eyes. One frog even has limbs coming out of its mouth. These are your observations , or things you notice about an environment using your five senses.
::想象一下你是一名科学家。在本地池塘采集水样时,你注意到一只五条腿而不是四条(图 ) 的青蛙。当你开始环顾四周时,你发现许多青蛙有多余的四肢、额外的或没有眼睛。一只青蛙甚至从嘴里伸出了四肢。这些是你的观察,或者你用五感知力观察环境。A frog with an extra leg. Identify a Question Based on Your Observations
::查明基于您意见的问题The next step is to ask a question about the frogs. You may ask, "Why are so many frogs deformed?" Or, "Is there something in their environment causing these defects, like ?" Yet, you do not know if this large number of deformities is "normal" for frogs. What if many of the frogs found in ponds and lakes all over the world have similar deformities? Before you look for causes, you need to find out if the number and kind of deformities is unusual. So besides finding out why the frogs are deformed, you should also ask: "Is the percentage of deformed frogs in this pond greater than the percentage of deformed frogs in other places?"
::下一步是询问有关青蛙的问题。你可能会问,“为什么这么多青蛙变形了?” 或者“在他们的环境中,有什么东西造成了这些缺陷,比如?” 然而,你不知道这大量的变形对青蛙来说是不是“正常 ” 。如果世界上在池塘和湖泊中发现的许多青蛙有相似的变形呢?在你寻找原因之前,你需要找出这些变形的数量和种类是否不同寻常。因此,除了找出青蛙为什么变形之外,你还应该问:“这个池塘中变形青蛙的百分比是否比其他地方变形青蛙的百分比高?”A pond with frogs. Research Existing Knowledge About the Topic
::有关专题的现有知识No matter what you observe, you need to find out what is already known about your questions. For example, is anyone else doing research on deformed frogs? If yes, what did they find out? Do you think that you should repeat their research to see if it can be duplicated? During your research, you might learn something that convinces you to change or refine your question. From this, you will construct your hypothesis.
::无论你观察什么,你都需要找出关于你的问题已经知道什么。例如,是否有其他人对畸形青蛙进行研究?如果是这样,他们发现了什么?你是否认为你应该重复他们的研究,看看是否可以重复?在你的研究中,你可能会学到一些东西,说服你改变或改进你的问题。从这一点上,你将构建你的假设。Construct a Hypothesis
::构造假说A hypothesis is a proposed explanation that tries to explain an observation. A good hypothesis allows you to make more predictions . For example, you might hypothesize that a pesticide from a nearby farm is running into the pond and causing frogs to have extra legs. If that's true, then you can predict that the water in a pond of non-deformed frogs will have lower levels of that pesticide. That's a prediction you can test by measuring pesticide levels in two sets of ponds, those with deformed frogs and those with nothing but healthy frogs. Every hypothesis needs to be written in a way that it can:
::假说是一个试图解释观察的假设。 一个好的假说允许您做出更多的预测。 比如, 您可能假设附近农场的杀虫剂 正在跑进池塘, 并导致青蛙多腿。 如果这是真的, 那么您就可以预测一个非畸形青蛙池中的水 将具有较低的农药水平。 这是通过测量两组池塘中的农药水平, 即那些有畸形青蛙的池塘和那些只有健康青蛙的池塘中的农药水平来测试的预测。 每个假说都需要写成能够做到的方式:- Be tested using experiments to collect evidence.
::利用收集证据的实验进行测试。
- Be proven wrong.
::证明是错的
- Provide measurable results.
::提供可衡量的成果。
- Provide yes or no answers.
::提供是或否答复。
For example, do you think the following hypothesis meets the four criteria above? Let's see. Hypothesis: "The number of deformed frogs in five ponds that are polluted with chemical X is higher than the number of deformed frogs in five ponds without chemical X." Of course, next you will have to test your hypothesis.
::例如,你认为以下假设符合上述四个标准吗?让我们看看。假说 : “ 五个被化学X污染的池塘中畸形青蛙的数量 高于五个没有化学X的池塘中畸形青蛙的数量。” 当然,接下来你必须测试你的假设。Test Your Hypothesis
::测试你的假说To test the hypothesis, an experiment will be done. You would count the healthy and deformed frogs and measure the amount of chemical X in all of the ponds. The hypothesis will be either true or false. Doing an experiment will test most hypotheses. The experiment may generate evidence in support of the hypothesis. The experiment may also generate evidence proving the hypothesis false. Once you collect your data, it will need to be analyzed.
::为了测试假设, 实验将会完成。 您将计算健康和畸形的青蛙, 并测量所有池塘中的化学X数量。 假设将是真实的或虚假的。 实验将测试大多数假设。 实验可以产生支持假设的证据。 实验也可以产生证明假设虚假的证据。 一旦您收集了数据, 就需要分析它 。Analyze Data and Draw a Conclusion
::分析数据并绘制结论If a hypothesis and experiment are well designed, the experiment will produce results that you can measure, collect, and analyze. The analysis should tell you if the hypothesis is true or false. Refer to the table for the experimental results ( Table ).
::如果假设和实验设计得当, 实验将产生可以测量、 收集和分析的结果。 分析应该告诉您假设是真实的还是虚假的。 参考实验结果的表格( 表 ) 。Polluted Pond Number of Deformed Frogs Non-Polluted Pond Number of Deformed Frogs 1 20 1 23 2 23 2 25 3 25 3 30 4 26 4 16 5 21 5 20 Average: 23 Average: 22.8 Your results show that pesticide levels in the two sets of ponds are different, but the average number of deformed frogs is almost the same. Your results demonstrate that your hypothesis is false. The situation may be more complicated than you thought. This gives you new information that will help you decide what to do next. Even if the results supported your hypothesis, you would probably ask a new question to try to better understand what is happening to the frogs and why.
::您的结果表明,两组池塘中的农药含量不同,但畸形青蛙的平均数量几乎相同。 您的结果表明, 您的假设是错误的。 情况可能比您想象的复杂得多。 这给了您新的信息, 有助于您决定下一步要做什么。 即使结果支持您的假设, 您可能还会询问一个新问题, 以便更好地了解青蛙身上发生的事情和原因 。Drawing Conclusions and Communicating Results
::得出结论和传播结果If a hypothesis and experiment are well designed, the results will indicate whether your hypothesis is true or false. If a hypothesis is true, scientists will often continue testing the hypothesis in new ways to learn more. If a hypothesis is false, the results may be used to come up with and test a new hypothesis. A scientist will then communicate the results to the scientific community. This will allow others to review the information and extend the studies. The scientific community can also use the information for related studies. Scientists communicate their results in a number of ways. For example, they may talk to small groups of scientists and give talks at large scientific meetings. They will also write articles for scientific journals. Their findings may also be communicated to journalists.
::如果假设和实验设计得当,结果将表明你的假设是真实的还是虚假的。如果假设是真实的,科学家们往往会继续以新的方式试验假设,以学习更多的东西。如果假设是假的,则结果可能被用来提出和测试新的假设。然后科学家们会将结果告知科学界。这将使其他人能够审查信息并扩大研究范围。科学界也可以将信息用于相关的研究。科学家们可以以多种方式交流其结果。例如,他们可以与小科学家团体交谈,并在大型科学会议上进行演讲。他们还将为科学期刊撰写文章。他们的调查结果也可以向记者们通报。If you conclude that frogs are deformed due to a pesticide not previously measured, you would publish an article and give talks about your research. Your conclusion could eventually help find solutions to this problem.
::如果你认为青蛙之所以畸形是因为以前没有测量过的农药, 你会发表一篇文章, 谈论你的研究。你的结论最终会帮助找到解决这个问题的办法。Discovering the Scientific Method
::发现科学方法A summary video of the scientific method is shown in this video by Teacher's Pet:
::这段影片由教师宠物拍摄:Further Reading
::继续阅读Summary
::摘要- To study new problems, scientists use the scientific method; this includes making observations, forming a hypothesis, designing an experiment, and drawing conclusions.
::为了研究新的问题,科学家们采用科学方法;这包括进行观察、形成假设、设计实验和得出结论。
Explore More
::探索更多Use the resource below to answer the questions that follow.
::利用以下资源回答以下问题。- Control Variables at (7:05)
::控制变量(7:05)
- What is the difference between a dependent and an independent variable?
::依赖变量和独立变量之间有什么区别?
- How many dependent variables do you want in an experiment?
::您在实验中想要多少个依附变量 ?
- What are control variables?
::什么是控制变量?
- Why are control variables important?
::为什么控制变量很重要?
Review
::回顾- What steps are usually included in the scientific method?
::科学方法通常包括哪些步骤?
- What are the features of a good hypothesis?
::好假设的特征是什么?
- Why is it important for a scientist to communicate the results and conclusions of a study?
::为什么科学家必须通报研究结果和结论?
- Make observations .
