WEAK NEGATIVE CORRELATION SCATTER PLOT SERIES

Please understand it well.In order to understand correlation and regression, students must first be familiar with scatter diagrams and the idea of a line of best fit.īivariate data is essentially data that comes in pairs, e.g (height, weight). A scatter diagram can have two independent variables.Ī scatter diagram is an important concept from a PMP exam point of view. To analyze the pattern of the relationship, you change the independent variable and monitor the changes in the dependent one. The first variable is independent, and the second variable is dependent on the first. It can be positive, negative, or not correlated at all. This relationship can be between two causes or a cause and an effect. Scatter diagrams are useful in determining the relationship between two variables. Data coverage should be wide for plotting a scatter chart.The more the data resemble a straight line, the stronger the correlation.You can plot the scatter diagram when you have a large amount of data.It can be a coincidence or caused by a third variable. It is not always guaranteed that two variables share a relationship if the chart shows a correlation.Points to Remember While Plotting Scatter Diagram For example, if there is any relation between the temperature rise with the equipment malfunctioning. To figure out if two variables share a relation.For example, working hours versus earnings. If two variables pair well together, you can draw a scatter plot to see their relation and correlation.You should use the scatter diagram in the following cases: The range of data flow, like the maximum and minimum values, can be determined.It is the best method to map out a non-linear pattern.It shows the relationship between two variables.This chart does not show you the relationship for more than two variables.It only shows the quantitative expression of quantitative change. A scatter diagram does not show a quantitative measurement of the relationship between the variables.Scatter diagrams cannot give you the exact extent of potential correlation.In either case, the independent variable does not affect the second variable it is not dependent.

WEAK NEGATIVE CORRELATION SCATTER PLOT SERIES

It might be a series of points with no visible trend or a straight, flat row of points. There isn’t any relationship between the two variables to be seen. This diagram is known as the “Scatter Diagram with Zero Degree of Correlation.”Īs the value of X increases, the value of Y will decrease, but the pattern is not clear.

Scatter Diagram with Strong Correlation.

Scatter Diagram with Moderate Correlation.

These are the most common in project management.ĭepending on the correlation, you can divide scatter diagrams into the following categories: I will discuss the two most popular based on correlation and slope of the trend. You can classify scatter diagrams in many ways. For example, you can use the fishbone diagram to find the two variables (cause and effect) and then use the scatter diagram to analyze their relationship. However, the fishbone or Ishikawa diagram can help you draw a scatter diagram. The scatter plot helps you analyze the correlation between the two variables. The fishbone diagram shows you the effect of a cause however, it does not show the relationship between these two. Note that these two diagrams are different. Many professionals believe that a scatter diagram is like a fishbone diagram because the latter includes two parameters: cause and effect. In that case, you can use any axis for any variable. There can also be two independent variables. It is not necessary to have a controlling parameter to draw a scatter diagram.

The independent variable operates as the control parameter because it influences the behavior of the dependent variable. In most cases, the independent variable is plotted along the horizontal (x-axis), and the dependent variable is plotted on the vertical (y-axis). This reveals the correlation between the two. Once the drawing is complete, you notice that the number of accidents increases as the speed of vehicles increases. You select the two variables, motor speed and the number of accidents, and draw up the diagram. You are analyzing accident patterns on a highway. Scatter diagrams can show a relationship between elements of a process, environment, or activity on one axis and a quality defect on the other axis.” Example of Using a Scatter Diagram After determining how they are related, you can predict the behavior of the dependent variable based on the independent variable.Ī scatter plot is useful when one variable is measurable while the other is not.ĭefinition: According to the PMBOK Guide, a scatter diagram is “a graph that shows the relationship between two variables.

The scatter diagram is considered the simplest way to study the correlation between these two variables.

Weak negative correlation scatter plot