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  • 定义独立和依赖变量

    Finding the Cure
    ::寻找治愈

    lesson content
    Medical Scientist

    Variables are a concept that is at the heart of science. While we generally define a variable as an unknown quantity in math, the value is typically unknown because the value can change. Variables do not have to have a numerical value. A variable could be used to represent the country a person was born in, whether someone  does or does not like milk, etc. This type of data is referred to as qualitative data.
    ::变量是一个属于科学核心的概念。 虽然我们通常将变量定义为数学中未知的数量, 但由于数值可以改变, 其值通常不为人所知。 变量不必有数值。 变量可以用来代表一个人出生的国家, 不论某人是否喜欢牛奶, 也可以用来代表一个人出生的国家。 这种类型的数据被称为定性数据 。

    Scientists use variables to help understand relationships. This process begins by collecting data. For example,  a medical scientist tests whether a certain medicine helps a patient with a certain illness.
    ::科学家使用变量来帮助理解关系。 这一过程从收集数据开始。 例如, 医学科学家测试某一种医学是否帮助病人患某种疾病。

    Discussion Question
    ::讨论问题

    A medical scientist tests whether a certain medicine helps a patient with a certain illness. How would the scientist go about testing this? What could be considered variables in this test?
    ::医学科学家测试某种医学是否帮助病人患某种疾病。 科学家将如何测试这一疾病? 在这一测试中,什么可以被认为是变量?

     

    Dependent and Independent Variables
    ::依赖变量和独立变量

    Before  you answer the questions above, first examine at the two types of variable: dependent and independent . A dependent variable is a variable whose value changes based on the value of another variable. An independent variable is a variable whose value does not change based on another variable.
    ::在回答上述问题之前,先检查两种变量类型:依附变量和独立变量。一个依附变量是一个变量,其价值变化以另一个变量的值为基础。一个独立变量是一个变量,其价值没有根据另一个变量变化。

    Example
    ::示例示例示例示例

    Noreen is an engineer who ran a test to determine whether solar panels produce more energy at warmer or cooler temperatures. She saw that solar produce more energy at cooler temperatures. Identify the dependent and independent variables in this scenario.
    ::Noreen是一位工程师,他进行测试以确定太阳能电池板是在更温暖的温度还是更冷的温度下产生更多能量。她看到太阳能在更冷的温度下产生更多的能量。确定这一假设情景中依附和独立的变量。

    The variables in this scenario are the temperature and the amount of energy produced. The dependent variable is the variable that changes as the result of another variable; in this case, the dependent variable is the energy produced since e nergy production depends on temperature. Producing more energy will not physically change the temperature but a change in temperature will change the energy produced. The  independent variable is the variable that does not change as the result of another variable; in this case, the independent variable is temperature.
    ::假设情景中的变量是温度和产生的能量量。 依附变量是因另一个变量而变化的变量; 在这种情况下,依附变量是因能源生产取决于温度而产生的能量。 产生更多的能量不会实际改变温度,但温度的变化会改变产生的能量。 独立变量是不会因另一个变量而变化的变量; 在这种情况下,独立变量是温度。

    Answer the  questions below to practice identifying dependent and independent variables.
    ::回答以下关于确定依附和独立变量的做法的问题。

     

     

     

    Finding the Cure Continued
    ::寻找治愈 继续

    In the opening activity,  you were posed with the following scenario: a medical scientist tests whether a medicine helps a patient with a certain illness. To test this, the scientist would give the medicine to one group of people with the illness and give a placebo to another group of people with the illness. If a higher rate of people from the group that received the medicine shows positive effects , then the medicine is considered to be successful in treating the illness.
    ::在开业活动中,你被置于以下情景中:医学科学家测试药品是否帮助患有某种疾病的病人。为了测试这一点,科学家将向一组患者提供药品,并向另一组患者提供安慰剂。 如果接受药品的人群中较高比例的人产生积极效果,那么该药物被认为能够成功地治疗该疾病。

    The variables are whether or not someone is taking the medicine and the health of the patient. Because the effect of the medicine on the patient’s health should depend on whether the person is taking the medicine, the health of the patient is the dependent variable and whether the patient is taking the medicine is the independent variable.
    ::变数是某人是否在服用药物和病人的健康。 因为药物对病人健康的影响应该取决于病人是否在服用药物,病人的健康就是依赖变量,病人是否在服用药物是独立的变量。

    In the following interactive, determine and define the independent and dependent variables in different scenarios.
    ::在下文互动中,确定和界定不同情景中独立和依附的变量。

     

    INTERACTIVE
    Finding the Cure Continued
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    • Select the right answer to each question based on the situation given.
      ::根据给定的情况,选择每个问题的正确答案。
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    Variable Conundrum
    ::不稳定的难题

    Dependent and independent can be applied to any scenario involving related variables.
    ::任何涉及相关变数的假设情况都可适用依赖性和独立性。

    Example
    ::示例示例示例示例

    Zoe is printing a picture. The picture can be any size, but the width should be half the length to keep the dimensions the same.
    ::Zoe 正在打印图片。 图片可以是任意大小, 但宽度应该为半长, 才能保持尺寸不变 。

    Use the interactive below to see how the dependent and independent variables can be switched in this scenario as long as the relationship between them is maintained.
    ::使用下面的交互效果来查看在这种假设情景中,只要保持依附变量和独立变量之间的关系,这些变量是如何被转换的。

     

    INTERACTIVE
    Variable Conundrum
    minimize icon
    • Drag the red point to change the length or width of the image. 
      ::拖曳红色点以更改图像的长度或宽度。
    • Press the button to switch between making length change based on width or making width change based on length.
      ::按下按钮在根据宽度作出长度变化或根据长度作出宽度变化之间切换。
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     Summary
    ::摘要

    • Variables are used to represent unknown quantities .
      ::变量用于表示未知数量。
    • A dependent variable is a variable whose value changes based on the value of another variable.
      ::依赖变量是一个变量,其价值变化以另一个变量的值为基础。
    • An independent variable is a variable whose value does not change based on another variable.
      ::独立的变量是一个变量,其值不根据另一个变量而改变的变量。