Detailed Explanation Of Box-Whisker Chart

A Box and Whisker Chart in Tableau is used to visualize data distribution, including the median, quartiles, and outliers. In a box plot, the minimum and maximum values that are not outliers are displayed by "whiskers" extending from both ends of a box, representing the interquartile range. This is a detailed tutorial on how to make a Box and Whisker plot in Tableau: 

The first involved in preparing this chart is 

We have to make sure that data is formatted correctly before connecting to Tableau, to work with Measures like sales, profit, age, and dimensions to break the data into categories like region, category, and product. 

Step 1: 

First,  drag the split dimension of our data into categories like Region products into columns shelf. 

Step 2: 

In this step, we need to drag the measures like sales, profit, and age to the rows shelf. 

Step 3: 

Now, in the Show Me drop-down, we have to select the box and Whisker chart to display our data in a clear visualization. 

After selecting the Box and whisker chart the visualization will be displayed like below. 

The calculation behind this visualization, In Box and Whisker Plot, the "box" is a key visual component that represents the interquartile range (IQR), which encapsulates the middle 50% of the data. While the "whiskers" display the range of data that falls outside the box but is still within a specified "acceptable" range, the box itself offers a concise assessment of the distribution and dispersion of the data. In particular, the box is intended to display the data's central tendency and variability. values for the given data.  

The interquartile range (IQR), which extends from the first quartile (Q1) to the third quartile (Q3), is represented by the box. Half of the data points fall inside the box, indicating that this range contains the middle 50% of the data.  

Components of the Box: 

Left Edge (Q1): The first quartile (Q1), or the 25th percentile of the data, is shown by the box's left edge. Twenty-five percent of the data points fall below this number.  

 Right Edge (Q3): The third quartile (Q3), or the 75th percentile of the data, is shown by the box's right edge. Seventy-five percent of the data points fall below this value.  

    Height of Box (IQR): The Interquartile Range (IQR), displayed by the box's height, is  

IQR = Q3 - Q1 

This IQR represents the spread of the middle 50% of data, so the larger the box the more data spread into the central data points. 

The median (Q2) is a line or marker that splits the data into two equal halves, and you will frequently see it inside the box. Since the median is the dataset's midway value, 50% of the data falls above it and 50% falls below it. 

Points that are plotted as individual points and are deemed outliers are those that are outside the whiskers, or beyond the fences. 

I hope now you better understand the cal culation behind the Box and whisker chart.