Continuing our series on the 7 quality tools, today we’ll discuss the Scatter Plot. The 4:27 minute video explains the Scatterplot in Six Sigma projects and the article below shows examples that you can apply in your own projects.
So, what is a scatter plot? The scatter plot is a chart that helps us visualize points relative to other variables. We would typically use a scatter plot to:
- Understand the behavior of a process
- See if two factors have a relationship
- And To visually show correlation between two factors
We’ll be going through a data set together so we can better understand scatter plots through a practical example. The example we’ll be going through is a data set on the age of cars and their miles per gallon. Before we go to the data set, let’s discuss the steps to creating a scatter plot. You can follow these steps to create a basic scatter plot:
- First, identify the purpose. In this step, clarify what you are trying to achieve with a scatter plot. In other words, be clear about the problem you are solving.
- Determine the two factors to compare. This is important and by determining the two factors, you will keep your analysis tight and focused.
- Identify the measures. In this step, you want to find the pairs of values and their measurement. The factors must be variables that is, they must be measurements on a continuous scale.
- Collect the data. We won’t go into sample statistics here, but you need to collect the data.
- Then plot the data.
- Interpret the data. Is there a relationship?
- Take action
Watch the movie below to learn more.