Scientific data are not taken for museum purposes; they are taken as a basis for doing something. If nothing is to be done with the data, then there is no use in collecting any. The ultimate purpose of taking data is to provide a basis for action or a recommendation for action. The step intermediate between the collection of data and the action is prediction.

W. Edwards Deming, On a Classification of the Problems of Statistical Inference, June 1942, Journal of the American Statistical Association. Dr. Deming wrote this article while he was working for the US Census Bureau.

This is a wonderful quote. If you collect and review data that isn’t used as the basis for action that is likely wasted effort and maybe should be eliminated.

Sometimes the data results are for monitoring a process; if the data shows a deviation from expected values then someone will act by looking to see what is going on. And it might be normally no action is needed because the result is within the range of expected values.

The point of data in the Deming management system is to aid in the continual improvement of results. Data should be used to measure the impact of experiments (using PDSA cycle) in order to further improve the process (continuing to “turn” the PDSA cycle – run additional experiments) and eventually decide the improvement is ready to be deployed more broadly.

Data shouldn’t just passively reside in spreadsheets. Data should be used to make decisions every day.

The quote also points out the importance of prediction in taking action to learn and improve. The importance of prediction is something that those that follow practices derived from Deming’s ideas but without referring to Deming often fail to appreciate.

“Planning requires prediction. Prediction requires a theory.” – Ron Moen

Related: Metrics are valuable when they are actionable – Enumerative (explain the results) and Analytic (improve the system) Studies – Management is Prediction