Scatter plots are data visualizations which show a relationship between two or three variables. Each point on the scatter plot is placed based on a corresponding number on the horizontal X axis and vertical Y axis. By analyzing dots on the graph as virtual line, viewer is able to conclude correlation of two variables leading to one out of three results: positive, negative, and uncorrelated. Positive correlation occurs when there is a visible line from bottom left to top right. This indicates positive relationship between two variables. On the other hand, a visible line drew from top left to bottom right represents a negative correlation of two variables. However, if there is no correlation found on graph, it is considered as uncorrelated.
By adding a Z axis the graph becomes 3D scatter plot. In a 3D scatter plot, correlation cannot be found if dots are distributed randomly.
Because scatter plots represent and visualize a relationship of two variables, formulating a hypothesis is necessary as pre-processing of the graph.
Good examples
![](https://di.samizdat.co/2019/content/images/2019/09/0922F48C-A837-4F3E-8D88-134F117EC1EA.jpeg)
![](https://di.samizdat.co/2019/content/images/2019/09/AA8A6C44-69CB-4354-9D6E-355698778666.gif)
![](https://di.samizdat.co/2019/content/images/2019/09/7302F260-D24D-4D00-94F3-CAE00FAD7906.png)
Bad example
![](https://di.samizdat.co/2019/content/images/2019/09/A8F6DAA2-9124-408A-B91B-65866F8FF7C5.gif)
![](https://di.samizdat.co/2019/content/images/2019/09/A21642A7-5595-4EFE-892B-D7B068478A1C.png)
![](https://di.samizdat.co/2019/content/images/2019/09/47847E79-18EB-4F21-A339-D599C520ED60.jpeg)