Complete Scatter Chart Guide
Scatter charts usually consist of a large body of data. Each row in the scatter chart data table is represented by a marker whose position depends on its values in the columns set on the X and Y axes. The relationship between two variables is called their correlation.
The Definition of Scatter Chart
Scatter chart is a graph of plotted points that show the relationship between two sets of data. Scatter charts are used to investigate the possible relationship between two variables that both relate to the same "event". Scatter charts are similar to line charts in that they use horizontal and vertical axes to plot data points. However, scatter charts have a very specific purpose. Scatter charts show how much one variable is affected by another.
There is a maxim in statistics that says, "correlation does not imply causality." In other words, your scatter plot may show that a relationship exists, but it does not and cannot prove that one variable is causing the other. There could be a third factor involved which is causing both, some other systemic cause, or the apparent relationship could just be a fluke. Nevertheless, the scatter plot can give you a clue that two things might be related, and if so, how they move together.
When to Use Line vs. Scatter Charts
Line charts provide an excellent way to map independent and dependent variables that are both quantitative. When both variables are quantitative, the line segment that connects two points on the graph expresses a slope, which can be interpreted visually relative to the slope of other lines or expressed as a precise mathematical formula.
Scatter plots are similar to line graphs in that they start with mapping quantitative data points. The difference is that with a scatter plot, the decision is made that the individual points should not be connected directly together with a line but, instead express a trend. This trend can be seen directly through the distribution of points or with the addition of a regression line. A statistical tool used to mathematically express a trend in the data.
If the markers are close to making a straight line in the scatter chart, the two variables have a high correlation. If the markers are equally distributed in the scatter plot, the correlation is low, or even zero.
Steps to Draw a Scatter Chart
Although it is quite convenient to use scatter chart for visually displaying data, drawing scatter chart by hand is still a little bit difficult for most of us. No worries, it is quite an easy job to draw a scatter chart with the help of scatter chart maker. Now, let me show you how to quickly and correctly draw a scatter chart step by step.
First things first, choose your favorite scatter chart shape from library which is on the left of the canvas.
Drag and drop the scatter chart shape you have chosen on the drawing page．On the upper right of the scatter chart shape you may find a floating button as the picture below shows.
There are lots of options on the floating button. The first option is "Load data from File", please kindly note the default format of our example data file is text (.txt) file. Tips: Edraw also supports csv file, text and csv file exported by Excel. If you installed Office Excel, Edraw can load xls and xlsx file.
You may also add or delete a point, set point number, set max and min value and hide data labels. The last option on the floating button is "Appearance Options". When you double click it, a small window like the picture below shows will appear.
You may customize other scatter chart features to make it look more attractive.