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  • 散放绘图中的线条模式

    Trends
    ::趋势趋势趋势趋势趋势趋势趋势趋势趋势趋势

    lesson content
    Tree rings are an example of data that may demonstrate trends.

    The most important benefit  of displaying bivariate data in a scatter plot is the ease with which trends can be identified. Trends are used to determine whether or not the two variables are related. A trend is when a change in one variable affects the other variable. Trends are extremely important in every branch of science. Trends can help us make sense of the world around us and help to make predictions. For example, a dendrologist, a scientist who studies trees, might expect to see a relationship between the number of tree rings and age. The more rings in the stump of a tree, the older the tree. Tree rings can also provide information about the climate and rainfall in the area over the life of the tree. All of these relationships began with data . Scatter plots allow us to find trends that signal relationships between variables. If the relationship forms a straight line, the trend is referred to as a linear pattern. The strength of a linear pattern can be observed by how closely the points come to forming a straight line. If the points are more spread out, then we say that the relationship is weak. If the points are closer to forming a straight line we say that the relationship is strong.
    ::在散射地块中显示双变量数据的最重要好处是,趋势很容易确定。趋势被用来确定这两个变量是否相关。趋势是当一个变量的变化影响到另一个变量时趋势。趋势在科学的每个分支中都极为重要。趋势可以帮助我们理解我们周围的世界,并有助于作出预测。例如,一位研究树木的科学家,可能看到树圈数和树龄之间的关系。树丛中的圆环越多,树龄越长。树圈也可以提供关于树木生命中该地区气候和降雨量的信息。所有这些关系都从数据开始。剪切图让我们能够找到显示变量之间关系的趋势。如果关系形成直线线线,趋势就被称为线性模式。线性模式的强度可以通过点越接近形成直线线来观察。如果点越分散,那么我们就会说关系就比较弱。如果这些点更接近直线,我们就会说这种关系是牢固的。

    Positive Trends
    ::积极趋势趋势

    A positive trend occurs if one variable increases when the other variable increases. This trend gives the appearance of moving upward from left to right much the way a line with a positive would. Below are two examples of scatter plots with positive trends. The first graph displays the total home runs over the history of professional baseball. The second graph displays the amount of CO2 produced into the air by California power plants based on how much energy was put in. 
    ::如果一个变量随着另一个变量的增加而增加,就会出现一个积极的趋势。 这一趋势显示从左向右移动, 与正向右移动的方式大致相同。 下面是分布图中具有积极趋势的两个例子。 第一个图显示专业棒球历史的全垒打总量。 第二个图显示加利福尼亚电厂根据投入多少能量而生成的二氧化碳数量。

    Negative Trends
    ::负趋势

     A negative trend occurs if one variable decreases when another variable is increased. This trend gives the appearance of moving downward from left to right much the way a line with a negative slope would. Below are two examples of scatter plots with negative trends. The first graph displays the average temperature of the Earth's atmosphere as the altitude from sea level increases. The second graph displays the efficiency of an engine based on its size. 
    ::如果一个变数在另一个变数增加时下降,就会出现负趋势。 这一趋势显示从左向右移动, 似乎与负斜度线向右移动的方式大致相同。 下面是两个有负趋势的散落块的例子。 第一个图显示随着海平面高度升高,地球大气的平均温度。 第二个图显示引擎根据其大小的效率。

    Discussion  Questions
    ::讨论问题 讨论问题

    1. Which graph has a stronger relationship? How do you know?
      ::哪个图表的关系更牢固?
    2. Why do you think the engine size vs. efficiency graph does not have as strong a relationship?
      ::为什么你认为发动机大小与效率图表 并没有那么强烈的关系?
    3. Do you think it is a coincidence that the engine size vs. efficiency graph is falling over time? Why or why not?
      ::你认为引擎大小与效率图的下降是巧合吗?为什么或为什么没有?
    4. If there is a relationship between engine size and efficiency, what could cause larger engines to be less efficient?
      ::如果发动机大小与效率之间有某种关系,那么,怎样才能降低大型发动机的效率?

        

    Use the interactive below to take a closer look at positive and negative trends. 
    ::利用下文的交互方式,更仔细地审视积极和消极的趋势。

    INTERACTIVE
    Positive and Negative Trends
    minimize icon
    • Drag the red points to see the difference between scatter plots that are positive and negative or strong and weak.
      ::拖曳红色点以看到正和负或强和弱的散块之间的差别。
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    Identifying Trends
    ::查明趋势

    Use the interactive below to  improve  your understanding  of positive and negative trends in scatter plots.  
    ::利用下面的交互方式来加深你对散地的正负趋势的了解。

    INTERACTIVE
    Identifying Positive and Negative Trends
    minimize icon
    • Use the drop down menus to identify the trend.
      ::使用下拉菜单来识别趋势 。
    • Press the button when it appears to check your answer.
      ::当它似乎检查您的回答时按下按钮 。
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    Summary
    ::摘要

    A positive trend occurs  when one variable increases while the other variable increases.
    ::当一个变数增加而另一个变数增加时出现正趋势。

    A negative trend occurs  when one variable de creases while the other variable in creases.
    ::当一个变数减少而另一个变数增加时出现负趋势。

    If a relationship forms a straight line, the trend is referred to as a linear pattern.
    ::如果关系构成直线,则趋势称为线性模式。

    • When a  linear pattern has a strong relationship the points are close to forming a straight line.
      ::当线性图案关系密切时,点数接近形成直线。
    • When a  linear pattern has a weak relationship the points are more spread out.
      ::当线性模式关系微弱时,点就会更加分散。