How to build a correlation field

If you assume that there is a relationship between the characteristics of the process or indicators, you can build a graph that will reflect it. The graph establishing the relationship between the variables is called the correlation field.

You will need

• - a number of distributions from a dependent and independent variable;

• - paper, pencil;

• - a computer and a program for working with spreadsheets.

Instruction manual

one

Choose two variables between which, as you believe, there is a relationship, usually take quantities that change over time. Note that one of the variables must be independent, it will act as a reason. The second one should change synchronously with it - decrease, increase or change randomly.

2

Measure the value of the dependent variable for each independent reading. Enter the results in a table, in two rows or two columns. To detect a connection, you need at least 30 readings, but to get a more accurate result, take care of having at least 100 points.

3

Build the coordinate plane, while on the ordinate axis, postpone the values ​​of the dependent variable, and on the abscissa, independent. Sign the axes and indicate the units of measure for each indicator.

4

Mark the points of the correlation field on the graph. On the abscissa axis, find the first value of the independent variable, and on the ordinate axis, find the corresponding dependent value. Draw perpendiculars to these projections and find the first point. Mark it, circle it with a soft pencil or pen. Construct all other points in the same way.

5

The resulting set of points is called the correlation field. Analyze the resulting schedule, draw conclusions about the presence of a strong or weak causal relationship, or its absence.

6

Pay attention to random deviations from the schedule. If, on the whole, a linear or other dependence is traced, but the whole "picture" is spoiled by one or two points that are away from the total population, they can be recognized as random errors and not be taken into account when interpreting the graph.

7

If you need to build and analyze a correlation field for a large amount of data, use programs designed to work with spreadsheets, for example, Excel, or purchase special programs.