Quality Glossary Definition: Scatter diagram Show
Also called: scatter plot, X-Y graph The scatter diagram graphs pairs of numerical data, with one variable on each axis, to look for a relationship between them. If the variables are correlated, the points will fall along a line or curve. The better the correlation, the tighter the points will hug the line. This cause analysis tool is considered one of the seven basic quality tools.
When to Use a Scatter Diagram
Scatter Diagram Procedure
Scatter Diagram ExampleThe ZZ-400 manufacturing team suspects a relationship between product purity (percent purity) and the amount of iron (measured in parts per million or ppm). Purity and iron are plotted against each other as a scatter diagram, as shown in the figure below. There are 24 data points. Median lines are drawn so that 12 points fall on each side for both percent purity and ppm iron. To test for a relationship, they calculate: Then they look up the limit
for N on the trend test table. For N = 24, the limit is 6. Scatter Diagram Example Additional Scatter Diagram ExamplesBelow are some examples of situations in which might you use a scatter diagram:
Scatter Diagram Considerations
Scatter Diagram ResourcesYou can also search articles, case studies, and publications for scatter diagram resources. BooksThe Quality Toolbox ArticlesPitch Perfect (Lean & Six Sigma Review) Learning the ins and outs of capability analysis by examining Pittsburgh Pirates starting pitcher Jameson Taillon’s performance using scatter diagrams. Adapted from The Quality Toolbox, ASQ Quality Press. What is the relationship between data and graphs?Many investigations in science are concerned with finding relationships between continuous variables. After collecting a set of data, the data points for two variables can be plotted on a graph, and then a line drawn that best expresses the apparent relationship suggested by the data. This is called a line of best fit.
Which chart shows the relationship between two variables?Scatter plot (scattergram)
It's perfect for searching distribution trends in data. The variable on the y-axis is a dependent variable while the x-axis variable – independent. Use it to check whether there is any relationship between two variables.
Which graph type is used to show relationship between two continuous variables?Scatter plots are used to display the relationship between two continuous variables x and y.
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