The scatter diagram, or scatter plot, is a type of mathematical diagram of XY coordinates used to display values for a set of data. Typically, one value is under control while the other varies based on our control. For a quality assurance example, our control may be the number of features, while the variable is the number of bugs. The data for a scatter diagram is based over time or experience.
A Pareto Chart allows you to quickly identify the problem areas of your application by reporting those areas that have the greatest number of issues. The philosophy of the Pareto Chart is based on the 80/20 rule – by identifying and fixing the larger areas first, the application can be stabilized a lot quicker. Or, more specifically, correcting 20% of the currently known bugs will stabilize 80% of the application.