Dot Plots is applied for time-series analysis with irregular intervals of time. This visualization is mentioned in the book “Now You See IT” by Stephen Few. For example, the below Dot Plots show the toxin level through the different date of testing:
- Excel Sample Download
- Dot Plots:
- NOTE: Creating this graph is easy by using Line with Marker graph and hiding the line. The reason to hide the line is that it is not sufficient to create the trend with the irregular time range.
APPLY FOR QUALITY CONTROL CHART
Dot Plots can be applied to create Quality Control Chart by using two more line as the upper and lower control limit. The example below demonstrate the quality control chart of a shirt manufacturer showing sample defects and range of control limit:
- The Upper Limit and Lower Limit is the additional series with Line showing the limit range of defects.
- Samples with defect out of range will be marked with the different color (red) to differentiate.
TIPS AND OPINIONS
- Color: Use proper color for Limit Line, here I use color light gray not to interrupt the point.
Few, S. (n.d.). Now you see it: Simple visualization techniques for quantitative analysis.