2.13
複数の棒グラフ
名前が示すように、複数棒グラフは棒グラフと同じですが、異なるデータ値間の関係を表す複数の棒があります。できるだけ多くのパラメータを含めることができます。ただし、各パラメータの測定単位は同じである必要があります。
複数の棒グラフの各棒または列はデータ値を表します。これらのグラフは、主に 2 つ以上のデ…
統計学、生物学、物理学、化学など、異なるコースに登録している男性と女性の学生の数を比較したいとします。このような、異なるカテゴリのデータセットの比較は、複数の棒グラフを使用して視覚化されます。
ここで、グラフには、2 つのデータ セットを示すためにギャップで区切られた 2 つのバー グループが含まれています。
この場合、黒いバーは男子学生の数を示し、青緑色のバーは女子学生の数を表します。
最初のバー セットは、統計学に在籍する男子 5 人の学生と 4 人の女子学生を示し、2 番目のセットは、生物学に在籍する男子 3 人と 5 人の女子学生を示します。
複数の棒グラフでは、指定されたデータセットの数に応じて、さまざまなカテゴリに任意の数の棒を追加できます。
複数の棒グラフは、複数のカテゴリ間のパターンを比較および分析するのに役立ちます。この棒グラフから、リンゴの売り上げが最も多かったのはどの日だったか、最も人気のある果物はどれかなどの質問に簡単に答えることができます。
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Q1: What is a multiple bar graph used for?
A multiple bar graph compares two or more sets of data across different categories. It displays multiple bars for each category, with each bar representing a different data value. This visualization helps identify patterns and answer comparative questions, such as which course has more female students or which product had the highest sales.
Q2: How do you read the axes on a multiple bar graph?
On a multiple bar graph, categories of different data types are listed along the horizontal x-axis, while frequency or data values are listed along the vertical y-axis. For example, when comparing student enrollment across courses, course names appear on the x-axis and the number of students appears on the y-axis. Bar heights directly correspond to the frequency values.
Q3: How many bars can you include in a multiple bar graph?
You can add any number of bars under various categories in a multiple bar graph, depending on the number of data sets you need to compare. However, each parameter must have the same unit of measurement. For instance, if comparing six students across four subjects, you would draw four bars for each student to represent their marks in each subject.
Q4: What is the difference between a bar graph and a multiple bar graph?
A bar graph displays a single set of data with one bar per category, while a multiple bar graph contains multiple bars per category to show relationships between different data values. Multiple bar graphs allow simultaneous comparison of two or more data sets, making them ideal for analyzing patterns across several categories with related information.
Q5: What are the limitations of using multiple bar graphs?
Multiple bar graphs often require additional explanation and may fail to expose key assumptions, causes, impacts, and underlying patterns. They can also be easily manipulated to give false impressions of the data. Despite their usefulness for comparison, these limitations mean they should sometimes be supplemented with other visualization methods for complete data analysis.
Q6: How do you organize data before creating a multiple bar graph?
Before creating a multiple bar graph, organize your data into a frequency distribution format with categories on one axis and corresponding values on the other. Ensure all parameters share the same unit of measurement. Group related data sets together so each category displays multiple bars side by side, making comparisons clear and patterns easily identifiable.
Q7: What types of comparisons can you make with a multiple bar graph?
Multiple bar graphs enable comparisons such as enrollment differences between male and female students across courses, sales variations of different products over time, or performance differences across multiple subjects for individual students. By analyzing bar heights within and across categories, you can identify trends, determine which groups are most popular, and compare relative magnitudes across data sets.