Basic Graphical Plots Series: Scatter Plot Overview

Basic Graphical Plot Series: A Scatter Plot Overview

A Scatter Plot is among one of the “7 tools of quality” (which i will cover in a separate blog sometime), the “Scatter Plot” (or Scatter Chart or Scatter Diagram) is a visual mechanism to identify/depict any relationship between two quantitative variables (or datasets/samples) that can be made available as a data-pair/set (x, y) where the set values can then be used as Cartesian coordinates to be plotted along x and y axis of a graph. The individual values of the set(x, y) are therefore displayed as dots on the graph. This way if there is any relationship between the values, that relationship or “trend” may be visualized easily. Another important use of a Scatter Plot is that they can also be used for plotting a single variable over time (time becomes the 2nd variable here).

A scatter plot can suggest following major kinds of correlations between variables:

  • Positive correlation (seen from a rising trend of dots),
  • Negative correlation (falling trend of dots),
  • No/null correlation (no clear trend, just a random scattering of dots).

Not mandatory, but a line of best fit (also called a “trendline”) may be drawn to further clarify the correlation between the two variables. Also, though the common Scatter Plot is drawn as any other graph along the x, y axis in 2 dimensions, it can be extended as a 3D scatter plot as well, where the inter-relationship between a set of 3 variables (trivariate data) can also be depicted visually, modern software allows this type of visualization as well.

A very simple and interesting 🙂 scatter plot example:

A Simple Scatter Plot ...

The clear “rising trend” seen here shows a “positive correlation” between temperature and cola-sales, the Cola Company was certainly pleased by higher temperatures :), you can learn how to exactly plot these graphs and more simple plots in the lean six sigma yellow belt (online) or higher programs by ProSigma.

While i have presented a very brief overview of a scatter plot in this blog, however, at the ProSigma workshops you will find that you will learn this and more by actually doing. We believe most of the Learning needs to be by experience and interactivity and our Lean Focus is simply unparalleled in India, and we make it available via a range of Lean Six Sigma programs designed to cater to every level of professional.

However, before we conclude this blog, for those who are new to Lean Six Sigma and are interested in more such topics do visit the rest of ProSigma’s blog section, or try our 100% Free Online Lean Six Sigma White Belt Certification. Or join one of our premium (paid) range of programs,

and, Advanced students will like the following:
 

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