Imagine that you need to figure out the relationship between two different kinds of data. How can you go about it? Enter Scatter Diagrams also known as Scatter Charts.
Let’s say you have worked with the Testing team to create new test cases. Now in order to see if the new test cases had any impact on the number of defects you found you need a scatter diagram. Example below,

So essentially, scatter diagrams are just an X, Y matrix that plots the relationship between two variables. This helps in determining whether a relationship exists. As you can see in the example above, as the number of passed tests went up, the number of defects found went down significantly.
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